Answer:
Water is a compound. It contains more than one element: hydrogen and oxygen atoms are joined together;
Why does the half-life of cancer treatment decay?
Answer:
The decay of radioactive elements occurs at a fixed rate. The half-life of a radioisotope is the time required for one half of the amount of unstable material to degrade into a more stable material. For example, a source will have an intensity of 100% when new. At one half-life, its intensity will be cut into 50% of the original intensity.
Explanation:
14. What is the total number of kilojoules of heat needed to change 150. G of
ice to water at 0°C?
Answer:
[tex]\boxed {\boxed {\sf 50.1 \ kJ}}[/tex]
Explanation:
When water changes from ice (solid) to water (liquid), it is melting or fusion. Therefore, we can use the following formula to find energy:
[tex]q=mH_f[/tex]
where q is the energy, m is the mass, and Hf is the heat of fusion.
1. Define Values
The mass is 150 grams. The heat of fusion for water is 334 Joules per gram.
[tex]m= 150 \ g \\H_f=334 \ J/g[/tex]
2. Calculate Energy
Substitute the values into the formula.
[tex]q=150 \ g * 334 \ J/g[/tex]
Multiply. Note that the grams (g) will cancel each other out and leave Joules as our units.
[tex]q=150 *334 \ J[/tex]
[tex]q=50100 \ J[/tex]
3. Convert Units
We found the answer in joules, but the question asks for kilojoules, so we must convert.
There are 1000 Joules in 1 kilojoule. Therefore, we can divide the joules calculated by 1000.
[tex]50100 \ J *\frac{1 \ kJ}{1000 \ J}[/tex]
[tex]\frac{50100 \ kJ}{1000 \ }[/tex]
[tex]50.1 \ kJ[/tex]
50.1 kilojoules are needed to change 150 grams of ice to water.
How many moles of sucrose are dissolved in 250 mL of solution if the solution concentration is 0.150 M?
Answer:
plz refer to the attachment above .
The number of moles of sucrose dissolved in 250 mL of solution will be = 0.375.
What is Molarity?The total number of moles of solute in a given solution's molarity is expressed as moles of solute per litre of solution. As opposed to mass, which fluctuates with changes in the system's physical circumstances, the volume of a solution depends on changes in the system's physical conditions, such as pressure and temperature.
M, sometimes known as a molar, stands for molarity. When one gramme of solute dissolves in one litre of solution, the solution has a molarity of one. Since the solvent and solute combine to form a solution in a solution, the total volume of the solution is measured.
Molarity Formula: (number of moles of solute) / volume
The ratio of the moles of the solute whose molarity needs to be computed to the volume of solvent needed to dissolve the supplied solute is the equation for determining molarity.
Molarity = (number of moles of solute) / volume
0.15 * 250/1000 = number of moles
Number of moles = 15/100 * 25/100 = 0.375
Therefore, the number of moles of sucrose dissolved would be 0.375.
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An element X on reacting with oxygen forms an oxide X2O. this oxide dissolves in water and turns blue litmus red. a) Identify the element X and mention the nature of the compound formed. b) Write a balanced chemical equation for the above reaction
Answer:
The unknown element is Carbon.
(a) X is Carbon, its oxide is of acidic nature
(b) C+ O2 → CO2
Explanation:
We are given an unknown element that reacts with oxygen.
X + O2 → XO2
It is given that the oxide XO2 turns blue litmus red which is shown by acids, so XO2 is an acidic oxide. Also X will be a Non metal because Non metallic oxide is Acidic in nature.
The Oxide XO2 is dissolving is water. The oxide upon reacting with water will give an Acid.
XO2 type of oxide is found in the 14th group of the periodic table generally
So we have options like C, Si and Ge as these only have the Acidic oxide.
But when it comes to reactivity with water Only Carbon satisfies the need so the unknown element X is C.
CO2 + H2O → H2CO3 which is an acid.
(a) Element X is Carbon (C), The nature of the compound formed is Acidic.
(b) The reaction given will be as follows
C+ O2 → CO2
Therefore the unknown element is Carbon.
Which cup has more thermal energy?
2 liter cup of milk
1 liter cup of milk
Both have the same amount of thermal energy
Question: Which cup has more thermal energy?
A. 2 liter cup of milk
B. 1 liter cup of milk
Answer: A. 2 liter cup of milk
Explanation:
We have milk in both of the containers. The milk in both containers is the same temperature, so we will have to measure the amount of molecules. The amount of molecules makes it warmer, and if it is warmer, that is more energy. 2 liters have more thermal energy than 1 liter, because it has more molecules.
Our answer is 2 liter cup of milk.
What is removed in the sedimentation process
suspended solids from water
2. How would a small change in the Sun's radiation affect our
ecosystems?
Answer: It could burn or freeze anything
Explanation:
Answer:
The carcinogen (U.V.) helps to stabilize the formation of clouds and maintain life in ecosystem.
If drastic changes were made to the radiation of sun, it will lead to ecological imbalance such as changes in O3 layer, etc and surely, the last day (D-day, what we majorly call) will come!
Genes are found inside chromosomes and DNA is contained in the genes.
True
False
I believe that's true.
Question 8 of 10
What will happen when a reactant is added to a system at equilibrium?
A. The system will remain at equilibrium.
B. Only the concentration of that reactant will change.
C. More reactants will form.
D. The equilibrium of the system will be upset.
SUBMIT
the equilibrium of the system will be upset
Explanation:
What's the Henry's law formula for gas concentration?
Describe one way that grazing animals, such as bison or cattle, help to maintain grassland ecosystems.
Answer:
They fertilize the land and help with overgrowth.
Explanation:
The one way that grazing animals help to maintain grassland ecosystems is: It enhance the plant to grow.
Ecosystems enables both living organisms such as animals and non living organisms such as plant to communicate with one another in an environment.
Grazing animals is essential as it help to maintain the grassland ecosystems by quicken and boosting the growth of plant which inturn help to maintain a very healthy and sustainable ecosystems.
Grazing lead to the restoration of habitat as it help to restore back any form of damaged that occur to the natural resources of ecosystems.
Learn more about ecosystems here:
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Don't help me
Ima fine.k!!!!!!!!
Answer:
ok!
Explanation:
What actions can you take to reduce your impact on science?
Answer:
Don't travel by air if you can avoid it because air travel uses up large amounts of fossil fuels and creates greenhouse gases. Dispose of any rubbish responsibly - it can be hazardous to wildlife. Use public transport, cycle or walk instead of using a car. Use facilities and trips run by local people whenever possible.
Answer:
Practicing recycling and green computing
What does bananas batteries and people have in common
What will most likely happen to the action of an enzyme from the small intestine if it is placed in
an environment similar to the environment in which enzyme C functions best?
Answer:
It would be able to function because the ph of the environment is similar to that of intestine.
Explanation:
The pH of the small intestine is eight. The enzyme would be able to function because enzyme C functions best at a Ph range around 8.
PLZ HELP! THIS IS DUE IN A FEW MINS!
What would happen to work and power if the mass of the person walking was increased or decreased? EXPLAIN.
Answer:
work and power increases or decreases opposite of the mass
Explanation:
This Is beacuse Work is the product of Mass, Gravity, and Height
What is the resultant pressure if 1.7 mol of ideal gas at 273 K and 2.79 atm in a closed container of constant volume is heated to 315 K? Answer in units of atm.
Answer: The resultant pressure is 3.22 atm
Explanation:
Gay-Lussac's Law: This law states that pressure is directly proportional to the temperature of the gas at constant volume and number of moles.
[tex]P\propto T[/tex] (At constant volume and number of moles)
[tex]\frac{P_1}{T_1}=\frac{P_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 2.79 atm
[tex]P_2[/tex] = final pressure of gas = ?
[tex]T_1[/tex] = initial temperature of gas = 273K
[tex]T_2[/tex] = final temperature of gas = 315 K
[tex]\frac{2.79}{273}=\frac{P_2}{315}[/tex]
[tex]P_2=3.22atm[/tex]
Thus the resultant pressure is 3.22 atm
Guys please help me this is for a final
What happens when you change only the number of electrons inside of an atom
Answer: Changing the number of electrons will change the overall charge on an atom.
Explanation:
An atom that loses electrons will become positively charged and an atom with added electrons will become negatively charged. ... A charged atom is called an ion.
PLEASE HELP I'LL GIVE YOU BRAINLIEST!!
What is a compound?
A. the center of an atom that is formed by neutrons, protons, and electrons
B. a tiny particle that makes up all matter
C. a molecule that is formed from two or more different types of atoms.
D. a molecule that is formed from the same type of atoms
Answer:
C
Explanation:
hypothesize why carbohydrates are found in plant cell walls
Answer:
Plants can split starch into it's simpler glucose units for use as energy when needed. Cellulose is known as a structural carbohydrate because of the fibers formed by it's molecules. It is the major component of plant cell walls and comprises over half of the carbon found on planets.
Explanation:
I majored in Chemistry
HELP! ASAP!!! WILL MARK BRAINLIEST!!
Which of the following compounds in the main group is an alkali metal? Question 7 options: Beryllium (Be) Rubidium (Rb) Hydrogen (H) Strontium (Sr)
Answer:
Rb
Alkali Metals are Group 1 so
Rb it isnt Hydrogen because it is a gas
Explanation:
____________________________ the cell organelle where cellular respiration occurs.
Answer:
Mitochondrion is the cell organelle where cellular respiration occurs.
Hope it helps ^^
Answer:
Mitochondria
I hope this helps!
Please Help Me Balance The equation!! will mark brainliest
Answer: XCl2(aq) + 2 AgNO3(aq) ---> X(NO3)2(aq) + 2 AgCl(s)
Explanation:
Hehe I remembered how...
Mention any two variables of Ideal Gas law
Answer:
Pressure (P) , Volume (V) , Temperature (T)
Explanation:
An ideal gas has three variables that define its state. They are: absolute pressure (P), volume (V), and absolute temperature (T). The ideal gas law defines how these state variables relate to each other
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Help please I’ll give you brain list
Answer:
A
Explanation:
PLEASE HELP ASAP!!!!!!!!
Answer:
You need to count all the atoms on each side of the chemical equation. once you know how many of each type of atom you have,you can only change the coefficient. (the numbers in front of the atoms or compounds
Determine whether each melting point observation corresponds to a pure sample of a single compound or to an impure sample with multiple compounds.
The question is incomplete, the complete question is;
Determine whether each melting point observation corresponds to a pure sample of a single compound or to an impure sample with multiple compounds.
Experimental melting point is BELOW literature value
Experimental melting point is CLOSE to literature value
WIDE melting point range
NARROW melting point range
Answer:
narrow melting point-pure sample of a single compound
experimental melting point is close to literature value-pure sample of a single compound
wide melting point range-impure sample of multiple compounds
experimental melting point is below literature value-impure sample of multiple compounds
Explanation:
The experimental melting point of a pure single compound is sharp and extremely close to the melting point of the substance as recorded in the literature. Usually, a pure substance melts within a narrow range of temperatures.
Impure samples of multiple compounds melt over a range of temperatures. Also if the experimental melting point is well below the record in literature, then the sample is contaminated by other compounds.
What is the formula for the compound formed by a magnesium cation (Mg2+) and a fluoride anion (F- )?
Answer:
MgF₂
Explanation:
Fluorine only has a 1- charge, so to satisfy the 2+ charge on magnesium–– you need 2 fluorine atoms to balance out the charges.
I JUST NEED HELP!!! ASAP!!1 PLEASE!!!
Which fundamental principle from chemistry states different samples of the same substance contain elements in the same proportions?
Question 15 options:
A)
Law of simple multiple proportions
B)
Plum-pudding model
C)
Law of constant composition
D)
Bohr model
Answer:
I believe its A) Law of simple multiple proportions
Explanation:
The law of definite proportions states that a given chemical compound always contains the same elements in the exact same proportions by mass.
Answer:
A) Law of simple multiple proportions
Explanation:
7. What is the name of: CH3-CH(CH3)-CH2- alky group? *
isopropyl
propyl
sec-butyl
butyl
Answer:
propyl
1-propylmethane or 2-methylpropane