Answer:
When wood is burned, it undergoes a chemical reaction called combustion, which produces heat, light, and various gases such as carbon dioxide, water vapor, and nitrogen oxides. These gases are released into the air, leaving behind a residue of ash that is much lighter than the original wood. Therefore, option A is the best explanation for what Courtney observes.
In science, what is it called when you have a statement that can be mathematically modeled, based
on repeated experimental observations, that describes some phenomenon of nature?
In science, a statement that can be mathematically modeled based on repeated experimental observations, that describes some phenomenon of nature, is called a scientific law. A scientific law is a descriptive statement that summarizes a pattern observed in nature, typically expressed as a mathematical equation or formula, which describes the behavior of a particular natural phenomenon under certain conditions. Scientific laws are generally considered to be well-established and reliable, based on the repeated empirical evidence and testing that supports them.
How many Hydrogen atoms in the formula 4H3O2
Answer:
Three atoms of Hydrogen.
Explanation:
There are four molecules of three Hydrogen atoms and two oxygen atoms.
Hope it helps.
Question 3 (1 point) The diagram on the below shows water molecules and ions from an NaCl crystal. What is the most likely reason that each water molecule is arranged so that the oxygen part of the molecule faces a sodium ion?
Answer:
There is attraction between oxygen atom and sodium ion due to their significant electonegative difference so therefore they face each other........
How do covalent bonds differ from ionic bonds?
Answer: Covalent bonds share electrons between two or more atoms. Ionic bonds form when two or more ions come together with charge differences.
Explanation:
Ionic bonds: atoms TRANSFER electrons
Covalent: atoms SHARE electrons
How is s,p,d,f blocks related to the type of element and its properties?
grouping elements into s, p, d, and f blocks allows us to predict the chemical and physical properties of elements based on their electron configurations and periodic table positions.
The periodic table's s, p, d, and f blocks refer to the arrangement of electrons in the atom's outermost energy level (valence shell), and they are related to the element's type and properties in several ways.
Atomic size increases from right to left within a period and from top to bottom within a group.
Ionization Energy: The energy required to remove an electron from an atom is referred to as ionisation energy.
Electronegativity: The ability of an atom to attract electrons towards itself in a chemical bond is measured by electronegativity.
Reactivity: An element's reactivity is determined by the number of valence electrons it possesses. Because the s-block elements have one or two valence electrons, they are extremely reactive.
Chemistry: Ionic compounds are formed by s-block elements with nonmetals, whereas covalent compounds are formed by p-block elements.
learn more about Electronegativity here:
https://brainly.com/question/14481608
#SPJ4
Calculate the expected vapor pressure (in atm) for a solution prepared by dissolving 183. 0 g fructose in 500. 0 ml of water. Fructose is a nondissociating molecule, with a molar mass
The expected vapor pressure of the solution prepared by dissolving 183.0 g of fructose in 500.0 mL of water is approximately 0.0301 atm.
The mole fraction of water in the solution can be calculated as follows:
Moles of water = (volume of water in liters) x (density of water) / (molar mass of water)
Moles of water = (500.0 mL / 1000.0 mL/L) x (0.9982 g/mL) / (18.015 g/mol)
Moles of water = 27.722 mol
Moles of fructose = (mass of fructose) / (molar mass of fructose)
Moles of fructose = 183.0 g / 180.16 g/mol
Moles of fructose = 1.016 mol
The total moles of solute and solvent in the solution are:
Total moles = moles of water + moles of fructose
Total moles = 27.722 mol + 1.016 mol
Total moles = 28.738 mol
The mole fraction of water in the solution is:
Mole fraction of water = moles of water / total moles
Mole fraction of water = 27.722 mol / 28.738 mol
Mole fraction of water = 0.962
Using Raoult's Law, the expected vapor pressure of the solution can be calculated as:
Vapor pressure = mole fraction of water x vapor pressure of pure water
Vapor pressure = 0.962 x 0.0313 atm
Vapor pressure = 0.0301 atm
learn more about moles here:
https://brainly.com/question/28239680
#SPJ4
One mole is a quantity unit that is always equal to __________________________.
Answer:
6.022 × 10²³ units of that substance
Explanation:
how many moles are in 7.14x10 molecules of O2
Answer:
1.186x10^12
Explanation:
(NEED HELP ASAP) Which statement is true about the particles of a solid when the solid changes into a liquid?
-They stop vibrating.
-Their kinetic energy increases.
-They move closer to each other.
-The attractive force between them increases.
When a solid changes into a liquid, the particles of the solid move farther apart and gain kinetic energy. Therefore, the statement that is true about the particles of a solid when the solid changes into a liquid is: their kinetic energy increases.
What is Kinetic Energy?
It is a scalar quantity and is dependent on the mass and velocity of an object. The formula for kinetic energy is:
Kinetic energy = (1/2) * mass * velocity^2
In a solid, the particles are tightly packed and vibrate in a fixed position. When the solid is heated or the pressure is reduced, the kinetic energy of the particles increases and they begin to vibrate faster and move slightly away from their fixed positions. This causes the solid to start melting and the particles begin to slide over each other, forming a liquid. Therefore, the particles of the solid move apart and gain kinetic energy when the solid changes into a liquid.
Learn more about Kinetic Energy from given link
https://brainly.com/question/25959744
#SPJ1
Potassium chlorate (KClO3) will decompose to potassium chloride (KCl) and oxygen (O2) in the reaction shown:
2KClO3(s) → 2KCl(s) + 3O2(g)
A chemist allows 20.0 grams of KClO3 to decompose and captures 6.7 grams of O2 as a
result.
Answer:
Explanation:
Theoretical yield is 7.9 g O2
% yield is actual/theoreticalx 100 = 6.7/7.9 X 100= 84.81 % O2
What mass og MgO is neded to produce 9. 38g of Na2O?
2NaCl+MgO=Na2O+MgCl2
The 6.10 g of MgO (Magnesium oxide) is needed to produce 9.38 g of Na2O(Sodium oxide).
To solve this problem, we need to use stoichiometry to relate the mass of Na2O produced to the mass of MgO used.
From the balanced chemical equation:
2 NaCl + MgO → Na2O + MgCl2
We can see that 1 mole of MgO produces 1 mole of Na2O. We can use the molar mass of Na2O to convert the given mass of Na2O to moles:
9.38 g Na2O x (1 mol Na2O / 61.98 g Na2O) = 0.1514 mol Na2O
Since 1 mole of MgO produces 1 mole of Na2O, we know that we need 0.1514 mol MgO to produce 0.1514 mol Na2O. Using the molar mass of MgO, we can convert this to mass:
0.1514 mol MgO x (40.31 g MgO / 1 mol MgO) = 6.10 g MgO
Therefore, 6.10 g of MgO is needed to produce 9.38 g of Na2O.
For such more questions on Stoichiometry
https://brainly.com/question/14935523
#SPJ4
Note: The question would be as
What mass of MgO is neded to produce 9. 38g of Na2O?
2NaCl+MgO=Na2O+MgCl2
what is the percent composition of salicylic acid?
The percent composition of salicylic acid is C7H6O3, or 60.87%C, 4.4%H, and 34.75%O
2 NaOH + H2SO4 → 2 H2O + Na2SO4
How many grams of NaOH are required to produce 16 g of H2O ?
7.3g of NaOH are required to produce 16 g of H2O
What are molecular weight ?
The entire mass of the atoms required to form a molecule per mole, expressed in grams, is what makes up the molar mass, also known as the molecular weight. Grams per mole are used to measure molecular mass. To determine molecular weight, count the atoms in each element and increase the result by the element's atomic weight.
Caustic soda or lye are two other names for sodium hydroxide. It is a typical ingredient in soaps and cleansers. Sodium hydroxide is a colorless, odorless solid at room temperature. Sodium hydroxide is a white, odorless liquid.
39 g of NaOH gives 18g of H2O
? g of NaOH gives 16g of H2O
i.e 18*16/39g
i.e. 7.3g of NaOH are required to produce 16 g of H2O
To learn more about molecular weight use:
https://brainly.com/question/26388921
#SPJ1
Explain how fossil fuels are formed from
living organisms on land and in sea.
Answer:
After millions of years underground, the compounds that make up plankton and plants turn into fossil fuels. Plankton decomposes into natural gas and oil, while plants become coal. Today, humans extract these resources through coal mining and the drilling of oil and gas wells on land and offshore.
Explanation:
Fossil fuels such as oil, coal and natural gas formed from living organisms on land and in sea are non-renewable resources created by the extinction of prehistoric plants and animals that are gradually being buried under rock layers.
Crude oil (also called crude oil or simply petroleum) is a fossil fuel formed from the remains of ancient marine organisms. After it died and sank to the bottom of the sea, the organic material mixed with other sediments and was buried.
Over the years, the rubble has been covered by layers of sand and silt. The heat and pressure of these layers helped turn the remains into what we now call oil or petroleum (fossil fuels).
To learn more about fossil fuels,
https://brainly.in/question/17658079
https://brainly.in/question/227555
14.87 moles of Magnesium should form 14.87 moles of Magnesium Chloride. 14.77 moles of Hydrochloric acid should form 7.97 moles of Magnesium Chloride. Only 1.78 moles of Magnesium chloride is obtained. What is the percent yield?
PLEASE HELP and teach please
According the question the Percent yield is 11.99%
What is yield?Yield is an economic term referring to the income generated by an investment over a period of time. It is usually expressed as a percentage of the initial investment and is calculated by taking the total income earned and dividing it by the initial investment. Yield is an important measure of the performance of an investment, and is a key factor in determining the attractiveness of an investment. Yields can be calculated for individual investments, or for portfolios of investments. Yields can also be calculated for different types of investments, such as stocks, bonds, and mutual funds. Yields are also used to compare investments with different levels of risk, so investors can make informed decisions about their investments. Yields are affected by a variety of factors, including interest rates, inflation, and market conditions.
The percent yield can be calculated using the formula:
Percent yield = (Actual yield / Theoretical yield) * 100
For Magnesium Chloride, the theoretical yield is 14.87 moles, and the actual yield is 1.78 moles.
Therefore, the percent yield is:
Percent yield = (1.78 / 14.87) * 100 = 11.99%
To learn more about yield
https://brainly.com/question/25996347
#SPJ1
For parts of the free-response question that require calculations, clearly show the method used and the steps involved in arriving at your answers. You must show your work to receive credit for your answer. Examples and equations may be included in your answers where appropriate. 2 NO₂(g) +F₂(g) → NO₂F(g) AH-284 kJ/mol,zn NO₂(g) and F₂ (g) can react to produce NO₂F(g), as represented above. A proposed mechanism for the reaction has two elementary steps, as shown below. Step 1: NO₂+ F₂ NO₂F + F (slow) Step 2: NO₂+F NO₂F (fast)
(a) Write a rate law for the overall reaction that is consistent with the proposed mechanism.
Rate law for the overall reaction that is consistent with the proposed mechanism is k [NO₂] [F₂].
What is rate law expression?
It is an expression that provides a relationship between the rate of the reaction and the concentrations of the reactants participating in it multiplying with rate constant. Rate in rate law expression is decided according to slow step.
Example-
If a reaction given as A + B → C rate constant = k
rate = k [A] [B]
Given,
Step 1: NO₂+ F₂ → NO₂F + F (slow)
Step 2: NO₂+F → NO₂F (fast)
rate = k [NO₂] [F₂]
Therefore, rate law for the overall reaction that is consistent with the proposed mechanism is k [NO₂] [F₂].
Learn more about rate law expression, here:
https://brainly.com/question/14779101
#SPJ9
What major type of weak interactions can asp have that are absent in chymotrypsin?
In the catalytic cycle, asp is capable of weak interactions with histidine that chymotrypsin does not have.
Throughout the catalytic cycle, Asp-102 maintains its negative charge. It establishes a salt bond with the protonated form of His-57 but not the deprotonated form, stabilizing the protonated form and boosting the histidine's affinity for protons.
The histidine residue interacts with aspartate and is oriented correctly as a result. Following that, histidine and serine's alcohol group may interact. Histidine changes serine from a weak nucleophile (alcohol) into a strong nucleophile by removing the hydrogen ion from the alcohol (alkoxide).
To know more about chymotrypsin, visit,
https://brainly.com/question/25752442
#SPJ4
What happens to the molecular attraction and kinetic energy when gas to changes to liquid?
Answer:
the molecules in a liquid don't move apart.
Explanation:
The molecules of a gas move apart when they collide. The average kinetic energy of the particles in a liquid (or solid) is small enough that the forces of attraction between them is sufficient to hold the particles close together. The molecules in a liquid (or solid) do not move apart.
Answer: When a gas changes to a liquid, the molecules in the gas lose some of their kinetic energy and their molecular attraction increases.
Explanation:
In a gas, the molecules are moving around rapidly and colliding with each other and with the walls of the container. These collisions create pressure, and the average kinetic energy of the molecules is high. However, when the gas cools down, the average kinetic energy of the molecules decreases, and they move around more slowly.
As the gas cools down further, the molecules start to come closer together, and the intermolecular attractive forces become more important. Eventually, the attractive forces between the molecules become strong enough to overcome the kinetic energy of the molecules, and the gas condenses into a liquid.
In a liquid, the molecules are still in motion, but they are much closer together and have much lower average kinetic energy than in a gas. The attractive forces between the molecules are strong enough to keep them close together in a fixed volume, but not so strong that they are unable to move around freely.
Pls answer number 4, my grade depends on it
Answer: where are the photographs
Explanation:
Identify the Name, Symbol, number of protons, neutrons, and electrons in a neutral atom of each of the following: (Please refer to a periodic table):
Answer:
Carbon
Name: Carbon
Symbol: C
Number of protons: 6
Number of neutrons: 6 or 7 (Carbon has two stable isotopes with 6 or 7 neutrons)
Number of electrons: 6
Sodium
Name: Sodium
Symbol: Na
Number of protons: 11
Number of neutrons: 12 or 13 (Sodium has one stable isotope with 12 neutrons, and another with 13 neutrons)
Number of electrons: 11
Helium
Name: Helium
Symbol: He
Number of protons: 2
Number of neutrons: 2
Number of electrons: 2
Chlorine
Name: Chlorine
Symbol: Cl
Number of protons: 17
Number of neutrons: 18 or 20 (Chlorine has two stable isotopes with 18 or 20 neutrons)
Number of electrons: 17
Gold
Name: Gold
Symbol: Au
Number of protons: 79
Number of neutrons: 118 (Gold has only one stable isotope with 118 neutrons)
Number of electrons: 79
Based on the color of the flame emitted by known compounds, what could be the metallic ion present in each of unknown solid
The color of the flame emitted by known compounds can be used to help identify the metallic ion present in an unknown solid. Different metallic ions produce different flame colors when they come into contact with a flame.
Metal ions in unknown substances can be identified through flame tests thanks to their distinctive emission spectra.
The metallic ion contained in an unknown material can be determined using the color of the flame produced by known compounds.
When in contact with a flame, different metal ions produce distinct flame colors: sodium creates a yellow flame, whereas potassium creates a violet flame.
The presence of a metallic ion can be determined by contrasting the flame colors of the known compounds with the flame of the unknown solid.
A spectroscope must be used to evaluate the flame in order to precisely identify the metal ions contained in an unidentified substance. This can lead to a more precise identification and a more thorough investigation of the emission spectra.
To know more about ion,
https://brainly.com/question/13692734
#SPJ4
When the same amount of force is applied to a smaller area, how is pressure affected?
Answer:
The pressure is reduced since the area needed to be exerted on by pressure has also been reduced
Please help! Ty
How many protons, neutrons,
and electrons are in this ion?
31 P3-
15
A. 15 p+, 16 nº, 18 e
B. 16 pt, 15 nº, 19 e
C. 15 pt, 16 nº, 15 e-
D. 15 pt, 16 nº, 12 e-
Explanation:
The symbol P represents the element phosphorus, which has an atomic number of 15, indicating that it has 15 protons in the nucleus. The ion is negatively charged with a 3- charge, which means it has three more electrons than protons.
To find the number of neutrons in an atom or ion, you need to know its mass number, which is the sum of protons and neutrons. Since the charge of the ion is not related to its mass, we can assume that the mass number is the same as that of the neutral phosphorus atom, which is approximately 31.
So, the number of protons, neutrons, and electrons in the P3- ion is:
Protons: 15
Neutrons: 31 - 15 = 16
Electrons: 15 + 3 = 18
Therefore, the P3- ion has 15 protons, 16 neutrons, and 18 electrons.
When a force is applied to an object, what happens?
The object changes its color.
The object changes its shape.
The object changes its motion.
The object changes its state.
When a force is applied to an object, the object changes its state. Therefore, the correct option is option D.
What is force?A force is an effect in physics that enables the movement of something with mass that change its velocity and accelerate. It may represent a push or perhaps a pull, with the direction and magnitude always present, making this one a vector quantity. It really is measured in newtons (N) and is denoted by the sign F.
Newton's second law, in its original form, states that perhaps the net force exerted on an object is equivalent to the pace that its momentum varies with time. When a force is applied to an object, the object changes its state.
Therefore, the correct option is option D.
To learn more about force, here:
https://brainly.com/question/13014979
#SPJ1
A liter of milk has a [H+] of about 2.51 × 10–7. (You may prefer to think of the hydronium ion concentration, [H3O+], as 2.51 × 10–7.) Use the formula for the calculation of pH provided and show each step as you calculate the pH of milk. In order to get full points you must show all the steps you take.
The pH of milk is approximately 6.6.
Steps
The formula for calculating pH is:
pH = -log[H+]
Given that [H+] of milk is about 2.51 × 10–7, we can substitute this value into the formula to calculate the pH:
pH = -log(2.51 × 10–7)
pH = -(-6.6)
pH = 6.6
Therefore, the pH of milk is approximately 6.6.
What is pH?A solution's acidity or basicity is determined by its pH. A pH of 7 indicates a neutral solution (equal concentration of H+ and OH- ions), a pH of less than 7 indicates an acidic solution (higher concentration of H+ ions), and a pH of greater than 7 indicates a basic or alkaline solution. It is defined as the negative logarithm of the hydrogen ion concentration [H+] in moles per liter (higher concentration of OH- ions).learn more about pH here
https://brainly.com/question/172153
#SPJ1
Calculate the energy of a photon with wavelength of 4.50 × 103 nm.
4.42 × 10–20 J
1.42 × 10–28 J
2.30 × 1045 J
4.71 × 10–29 J
Answer: 4.71 × 10–29 J
Explanation:
Question
3. Calculate the energy of a photon with a wavelength of 4.50 x 103 nm. 1 point 4.71 x 10-29) 1.42 x 10-28) 4.42 x 10-20) 2.30 x 1045)
Pine trees, strawberry plants, and cacti are all plants. Name charateristics that you think scientists could use to seperate these members of the Plantae kingdom into smaller groups
The characteristics that separate Pine trees, strawberry plants, and cacti of the Plantae kingdom into smaller groups is Gymnosperm or angiosperms, seeds, location.
All plants belong to the kingdom Plantae. They are multicellular, eukaryotic, and autotrophic creatures. A stiff cell wall is present in each plant cell. Chloroplasts and the pigment chlorophyll are present in plants, which are necessary for photosynthesis.
Plant species can be distinguished by the following characteristics:
Angiosperms or gymnosperms: Strawberry plants are angiosperms, but pine trees are gymnosperms. Cactus is a gymnosperm as well.
Plants can be classified according on their habitat. Cactus, for example, is a desert plant, although pine and strawberries are not. They are either seed-producing or spore-producing plants; pines are spore-producing plants. Strawberry plants produce seeds.
Learn more about Plantae kingdom:
https://brainly.com/question/14371358
#SPJ4
Floods can drastically change the land in an area due to
Explanation:
Floods can drastically change the land in an area due to what is known as erosion. Erosion is the process of water carrying away small pieces of rock and soil. Over time, this can lead to large changes in the landscape. Floods can also deposit sediment, which can change the land in a different way. Deposition is the process of sediment being left behind by water. This can cause the land to become higher in some areas and lower in others.
How many moles of helium gas would be required to fill a 22 L container at a temperature of 35 oC and a pressure of 3.1 atm?
To solve this problem, we can use the ideal gas law:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin.
We need to convert the temperature from Celsius to Kelvin by adding 273.15:
T = 35°C + 273.15 = 308.15 K
We also need to convert the volume from liters to cubic meters:
V = 22 L = 0.022 m³
Now we can solve for n:
n = PV / RT
n = (3.1 atm) (0.022 m³) / (0.08206 L·atm/mol·K) (308.15 K)
n = 0.00268 mol
Therefore, we would need 0.00268 moles of helium gas to fill a 22 L container at a temperature of 35°C and a pressure of 3.1 atm.
What is pressure?
It is typically measured in units of Pascals (Pa) or atmospheres (atm). Pressure can be calculated using the equation P = F/A, where P is pressure, F is the force being applied, and A is the area over which the force is being applied.In a gas, pressure is the result of the collisions of gas particles with the walls of the container. The more particles there are in a given volume, the higher the pressure will be. Additionally, increasing the temperature of a gas will increase the pressure if the volume and number of particles are held constant, due to the increased speed and force of the gas particles.To know more about pressure, click the link given below:
https://brainly.com/question/12971272
#SPJ1
PLEASE HELP!!
Classify each reaction as synthesis, decomposition, single replacement, double
replacement, or combustion.
>
NaOH + CuSO4 → Na2 SO4 + Cu(OH)2
C12H22O11 + O2CO2 + H₂O
NH4NO3 → N₂O + H₂O
BaCl2 + Na2 SO4 → BaSO4 + NaCl
1. synthesis
2. decomposition
3.single
4double displacement
5.combustion
Answer:
NaOH + CuSO₄ → Na₂SO₄ + Cu(OH)₂ is a double displacement reaction
C₁₂H₂₂O₁₁ + 12O₂ --> 12CO₂ + 11H₂O. This is a combustion reaction, as it involves a fuel reacting with oxygen to form carbon dioxide and water. However, this is not a balanced equation and so I have added in the correct ratios to balance the equation.
NH₄NO₃ → N₂O + 2H₂O. This is a decomposition reaction, as it involves the compound ammonium nitrate, 'decomposing' or breaking down into smaller components: dinitrogen oxide and water
BaCl₂ + Na₂SO₄ → BaSO₄ + 2NaCl. This is a double replacement reaction