Answer:
79.7 g He
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:
Step 1: Define
1.20 × 10²⁵ atoms He
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of He - 4.00 g/mol
Step 3: Convert
[tex]1.20 \cdot 10^{25} \ atoms \ He(\frac{1 \ mol \ He}{6.022 \cdot 10^{23} \ atoms \ He} )(\frac{4.00 \ g \ He}{1 \ mol \ He} )[/tex] = 79.7077 g He
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
79.7077 g He ≈ 79.7 g He
24. The density of silver at 20 °C is
10.5 g/cm³. What is the
volume of a 68-g bar of silver?
volume=6.5cm³
Explanation:
density= mass/ volume
volume= mass/ density
= 68/10.5
=6.5cm³
How many milligrams of sodium chloride are in a liter of solution that has 4.50 x 10-6 kg of sodium per liter?
The mass of sodium chloride that is present in a liter of solution that has 4.50 x 10⁻⁶ kg of sodium per liter is 45 mg.
What is the mass of sodium chloride in milligrams that is present in a liter of solution that has 4.50 x 10⁻⁶ kg of sodium per liter?The mass of sodium chloride in milligrams that is presents in a liter of solution that has 4.50 x 10⁻⁶ kg of sodium per liter is calculated as follows:
mass = mass concentration * volume in litersMass concentration of sodium chloride solution = 4.50 x 10⁻⁶ kg of sodium chloride per liter.
Volume of solution = 1 liter
Mass of sodium chloride = 4.50 x 10⁻⁶ kg/L * 1 L
mass of sodium chloride = 4.50 x 10⁻⁶ kg
mass of sodium chloride = 4.50 x 10⁻⁶ kg * 1000000 mg/kg
mass of sodium chloride = 45 mg
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A pictorial representation of an electron configuration is shown give the full electron configuration do not use a noble gas abbreviation.
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p
what is the electron configuration?
Name the element, assuming that the configuration describes a neutral atom.
The electron configuration is 1s², 2s², 2p⁶, 3s²,3p⁶, 4s², 3d¹⁰, 4p⁵ i.e. 35 that is bromine.
What is electronic configuration?Electronic configuration is defined as the arrangement of electrons around the nucleus of a particular atom or molecule.
An atom is made up of particles like protons, neutrons and electrons.
A neutral atom are the atoms with same number of protons and electrons.
Electronic configuration of an atom is defined as distribution of electrons in atoms shells and sub shells.
Bromine is element with symbol Br and atomic number 35. It is a oily liquid with a sharp smell, it is toxic in nature.
The neutral atom of bromine has 35 electrons as the neutral atom has same number of electrons and protons.
Thus, the electron configuration is1s², 2s², 2p⁶, 3s²,3p⁶, 4s², 3d¹⁰, 4p⁵, i.e. 35 that is bromine.
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Which periodic trend is not explained by shielding and ENC?
O Atomic radius
O ENC does not explain any periodic trend
O ENC explains all periodic trends
O
Electronegativity
ENC explains all periodic trends
The electrostatic attraction between the positively charged nucleus and the negatively charged electrons holds electrons in an atom or ion. Due to electron shielding that exists between the electron of interest and the nucleus in multi-electron species, the electrons do not experience the full positive charge of the nucleus. The effective nuclear charge is the total positive charge that really affects an electron.
In order to comprehend periodic characteristics, it is crucial to understand the idea of effective nuclear charge (Z*). The portion of the total nuclear charge that an electron in an atom experiences is known as the effective nuclear charge. This is equal to the atomic number (Z) less the amount () by which other atoms' electrons protect the particular atom's nucleus.
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for the measurements 0.123 m, which digits is the estimated digit?
Answer:
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Explanation:
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Which example shows an organism that cannot reach homeostasis through internal changes?
Responses
A lizard is cold, and it moves to a sunny rock to warm up.
A dog shivers when it is too cold.
Circulation decreases in a bird when it becomes too warm.
.
A person gets a fever in response to a flu infection.
pls help!
EXPERIMENTAL QUESTION: How does the amount of substance affect the rate at which temperature changes?
HYPOTHESIS: If the mass of a sample of water is increased, then the rate at which its temperature changes will be ____________________.
increased
decreased
Answer:
I'm guessing you are asking for the word that will make the hypothesis correct. In that case, it would be:
"If the mass of a sample of water is increased, then the rate at which it's temperature changes will be decreased."
Explanation:
Mass and temperature have an inverse relationship, so when one of the values increase, the other decreases. On Study.com there is more on this subject. I will put a link for you :)
https://homework.study.com/explanation/how-does-the-amount-of-a-substance-affect-the-rate-at-which-temperature-changes.html#:~:text=For%20a%20given%20amount%20of,a%20smaller%20increase%20in%20temperature.
I hope this helps!
there are 393939 students in ms. salazar's chemistry class. if ms. salazar divides the class into 999 lab groups of 444 or 555 students each, what would be the number of lab groups with 555 students?
The total number of lab groups with 555 students is 447.
The total no. of students = 393939
Division of class into labs = 999
Let us consider there are two types of lab
No. of students in one type of lab = 444
No. of students in another type of lab = 555
Let the no. of labs which have 555 students = x
Then, remaining labs which contain 444 students can be calculated as
Total lab - x
= 999 - x
Calculation:Now, according to the question,
555( x) + 444 (999 - x) = 393939
555x + 443556 - 444x = 393939
-111x = - 49617
111x = 49617
x = 49617/ 111
x = 447
Thus, we calculated that the total number of lab groups with 555 students is 447.
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Help! What role does lactase play in breaking apart the disaccharide lactose?
lactase provides a binding site for lactose to initiate chemical breakdown.
lactase lowers the activation energy needed to begin breaking down lactose.
lactase releases heat during the breakdown of lactose.
lactase prevents too many disaccharide molecules from clumping together during chemical reactions
Lactase lowers the activation energy needed to begin breaking down lactose and is the role it plays in the reaction which is therefore denoted as option B.
What is an Enzyme?This is referred to as a biological catalyst which increases the rate of a chemical reaction and is usually specific in nature. Examples include lactase,amylase which have substrates such as lactose and starch respectively.
Lactase which is an enzyme is involved in the breaking apart of the disaccharide known as lactose by lowering the activation energy thereby increasing the rate of the reaction and ensuring that is easily done.
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Transferring small quantities of liquid solutions from one container into another
Using Pasteur Pipettes (or pipets) are the most commonly used tool for transferring small volumes of liquids (< 5mL) from one container to another.
What is Pasteur Pipettes?A pipette, also called pipett, is a lab instrument frequently used in the fields of chemistry, biology, and medicine to transfer a predetermined volume of liquid, frequently as a media dispenser. Pipettes are available in a variety of styles with varying degrees of accuracy and precision, ranging from simple single-piece glass pipettes to more intricate adjustable or electronic pipettes. In order to draw liquid up and out of a pipette, a partial vacuum is often created above the liquid-holding chamber and then selectively released. Depending on the instrument, measurement accuracy varies substantially.
Although each form of pipette has particular descriptive titles, in practice any sort of pipette will only be referred to as a "pipette," and the required device will be clear from the context. Occasionally, pipettes that dispense.
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triaryl-1,3,5-triazinane-2,4,6-triones (isocyanurates) peripherally functionalized by donor groups: synthesis and study of their linear and nonlinear optical properties
the synthesis study of triaryl-1,3,5-triazinane-2,4,6-triones is functionalized by d6-transition metal acetylides complexes at their periphery .
triaryl-1,3,5-triazinane-2,4,6-triones (isocyanurates) peripherally functionalized by donor groups: The linear optical (LO) and nonlinear optical (NLO) properties of a series of isocyanurates functionalized by donor's arms at the periphery. These octupolar derivatives were obtained from commercial isocyanate derivatives several of these derivatives exhibit remarkable transparency or activity/ tradeoffs. In third‐order activity, the stronger donor groups (X=NH2, NMe2, or NPh2) with the longer derivatives possess effective two‐photon absorption cross sections displayed for the extended arylamino cyclotrimers. to rationalize their non linear properties and unravel their electronic structures DFT computations were also performed.
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Determine the mass of barium carbonate containing 10% impurities if 6.72 liters of CO2 were formed when hydrochloric acid was added to it
The mass of barium carbonate containing 10% impurities if 6.72 liters of CO₂ were formed when hydrochloric acid was added to it is 65.78 g.
What is the mass of barium carbonate containing 10% impurities if 6.72 liters of CO₂ were formed when hydrochloric acid was added to it?The mass of barium carbonate containing 10% impurities that produced 6.72 liters of CO₂ when hydrochloric acid was added to it is determined from the equation of the reaction as follows:
Equation of the reaction: BaCO₃ + 2 HCl → BaCl₂ + H₂O + CO₂
Based on the equation of the reaction, 1 mole of barium carbonate produces 1 mole of CO₂.
1 mole of CO₂ has a volume of 22.4 liters
6.72 liters of CO₂ = 6.72/22.4 moles
6.72 liters of CO₂ = 0.3 moles
Moles of BaCO₃ reacted = 0.3 moles
Molar mass of BaCO₃ = 197.34 g/mol
Mass of 0.3 moles of BaCO₃ = 0.3 * 197.34 g/mol
Mass of 0.3 moles of BaCO₃ = 59.2 g
Since the barium contains 90% pure BaCO₃ and 10% impurity,
Mass of barium carbonate reacted = 59.2 g/0.9
Mass of barium carbonate reacted = 65.78 g
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what is the simple unit factor that relates the number of hydrogens in sucrose to the number of oxygens?
The simple unit factor that relates the number of hydrogens in sucrose to the number of oxygens is:
2 moles hydrogen = 1 mole of oxgen
Formula of sucroseThe formula of sucrose is given as follow:
C₁₂H₂₂O₁₁
From the formula, we obtained the following
12 moles of carbon22 moles of hydrogen11 moles of oxygen How to determine the unit that relates hydrogen and oxygen1 mole of C₁₂H₂₂O₁₁ contains:
22 moles of hydrogen11 moles of oxygenThus, the unit factor that relates hydrogen and oxygen can be obtained as follow:
Hydrogen / Oxygen = 22 / 11
Hydrogen / Oxygen = 2 / 1
Thus,
2 moles hydrogen = 1 mole of oxgen
Thus, for every mole of oxygen, there are 2 moles of hydrogen
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based on the law of multiple proportions, how many grams of hydrogen would you expect 2.19 g of nitrogen to combine with to yield ammonia?
We're going to use 0.34 grams of nitrogen to resolve this. This would have a molar mass of, uh, 28 2 grams if we converted these two moles. Wu will then combine this as well. One-mole play is also a thing. three of H 2's moles. Grams of hydrogen are what we need. We will learn the answer here. Hydrogen weighs two grams per mole. Each gram weighs 0.501 grams. That would thus stand in for this. 2.34 grams of nitrogen would need to react with 0.501 grams of hydrogen to produce ammonia. 241=2 moles of nitrogen and 243=6 moles of hydrogen will be converted into 4 moles of ammonia. Nitrogen has a molar mass of 28 g/mol and hydrogen has a molar mass of 2 g/mol.
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practice entering numbers that include a power of 10 by entering the diameter of a hydrogen atom in its ground state, dh
A hydrogen atom's diameter in its ground state is 1.06 x 10^-10 metres.
What makes up an atom of hydrogen?The hydrogen atom is the most basic of all the atoms because it only has one proton and one electron. There are two other hydrogen isotopes, deuterium and tritium, in addition to protium, which is the most prevalent form of the atom.The three known isotopes of hydrogen. The isotopes of hydrogen with mass numbers 1, 2, and 3What do you call two hydrogen atoms?Hydrogen gas molecules are composed of two hydrogen atoms bound together by a covalent bond. In other compounds, such as water with an oxygen atom and hydrocarbons with carbon atoms, hydrogen atoms also form covalent connections.learn more about hydrogen atom here
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the question you are looking for is
Practice entering numbers that include a power of 10 by entering the diameter of a hydrogen atom in its ground state, dh= 10.6x10^-11m, into the answer box.
Which of these is true for a molecular model like the one shown ? A. We can always identify the type of each atom based on color. B. The model shows how the various atoms are connected in the molecule. C. The model shows the actual size of each atom correctly D. The model shows the relative sizes of the atoms to each other.
The true statement about the model is that the model shows how the various atoms are connected in the molecule.
What is a molecular model?A molecular model is a representation of a molecule. We know that the molecular model shows the extent to which the atoms are bonded in the compound. The model gives us an idea of the intricate atom to atom arrangement that exists in the molecule that is under study.
Now we know that the atoms that are in the models must be shown by the use of different colors. This enables us to be able to effectively and properly distinguish between the atoms of the compound as shown in the model.
The true statement about the model is that the model shows how the various atoms are connected in the molecule.
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(b) .In an experiment, carbon (IV)oxide gas as passed over heated charcoal and the gas produced collected as shown in the diagram below Write an equation for the reaction that took place in the combustion tube (1mk)
When carbon (IV)oxide gas is passed over heated charcoal ,the gas produced is Carbon Monoxide.
The oxidation state of carbon (II) oxide, often known as carbon monoxide, is +2. It is the suffocating gas created when gasoline in car engines burns inefficiently. Colorless, tasteless, odorless, and somewhat less dense than air, carbon monoxide is a gas. It is formed due to incomplete combustion of CO2. Carbon monoxide is much more threatening than CO2.
When carbon (IV)oxide gas is passed over heated charcoal ,the gas produced is Carbon Monoxide is Carbon (II) oxide is formed.
When coke or red-hot carbon is passed through carbon (IV) oxide, it is created.
The equation for the reaction is-
CO₂(g) + C(s) → 2CO(g)
Hence, Carbon monoxide is formed when Carbon dioxide is passed over heated charcoal.
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Which of the following are homogenous mixtures?
1. Solid steel
2. An aqueous solution of salt
3. Molten salt
A) 2 and 3
B) 1, 2, and 3
C) 1 and 3
D) 1 and 2
Thanks!
Answer:
i aint go the f 40
Explanation:
swervin how u look so perfect on ur worst day
Calcium carbonate decomposes into calcium oxide and carbon dioxide. If 224 g of calcium carbonate decomposes, how many moles of carbon dioxide gas is produced?.
When 224 g of calcium carbonate(CaCO3) decomposes , 2.24 moles of carbon dioxide is produced.
When calcium carbonate decomposes in the presence of heat, it produces calcium oxide and carbon dioxide. This reaction is represented by the following equation:
CaCO3 ⇒ CaO + CO2
It is clear from the above equation that,
1 mole of CaCO3 produces 1 mole of CO2
Or 100 g of CaCO3 produces 1 mole of CO2
Thus, 224 g of CaCO3 produces 1/100 x 224 = 2.24 moles of CO2
Therefore, if 224 g of calcium carbonate(CaCO3) decomposes, 2.24 moles of carbon dioxide is produced.
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Why is it important to water your house plants?
So they can have nutrients from the water to keep it from not dying
Answer:
Plants need water to grow. Plants are about 80-95% water and need water for multiple reasons as they grow including for photosynthesis, for cooling, and to transport minerals and nutrients from the soil and into the plant.
What happens when you add a proton to make lithium more positive. Do you get a lithium cation or do you get something else?
When you add a proton to make lithium more positive we get beryllium
When you add a proton to make lithium more positive and does't make lithium cation it make beryllium and isotope of beryllium that is an ion, as it has one less electron than the protons and the only factor that determines the identity of your element is the proton number when we added a proton in lithium then we get beryllium and new atom would not actually be an atom if add one proton and when adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom's atomic number
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Select the correct answer. what is tempera? a. pigment mixed with egg yolk as a binder. b. pure, undiluted pigment. c. pigment made from zinc and cobalt.
The correct answer is (A) pigment mixed with egg yolk as a binder.
A natural emulsion that is water-soluble, such as glue, honey, milk in the form of casein, or a variety of plant-based gums, can hold pigment in tempera, a painting media.
Using tempera, you can blend the essential colours as you go while creating the paint from scratch. Although it should be noted that some pigments require more binder than others and that the more egg added, the more transparent the resultant paint will be, mixes should begin with an equal volume of pigment and binder.
From the early 1500s, when oil paints started to gain popularity, tempera served as the main painting medium, it was employed for icon painting and painted panels in churches, and it is still utilised today.
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A certain liquid has a density of 2.67 g/cm3. 30.5 mL of this liquid would have a mass of
Taking into account the definition of density, the mass of the liquid is 81.435 grams.
Definition of densityDensity is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space and it measures the amount of mass in a given volume of a substance.
The expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:
density= mass÷ volume
Mass of the liquidIn this case, you know that:
Density= 2.67 g/cm³Volume= 30.5 mL= 30.5 cm³ (being 1 mL= 1 cm³)Replacing in the definition of density:
2.67 g/cm³= mass÷ 30.5 cm³
Solving:
mass= 2.67 g/cm³× 30.5 cm³
mass= 81.435 g
In summary, the mass of the liquid is 81.435 grams.
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when all quantum numbers are considered, how many different quantum states are there for a hydrogen atom with n
When all quantum numbers are considered, there are three (3) quantum states for hydrogen atoms.
The 3 quantum numbers of hydrogen is n, l and m.
n = principal quantum number, l = angular momentum quantum number,
m = angular momentum projection quantum number.
The hydrogen atom is simple and consists of a single negatively charged electron which moves around a proton which is positively charged. For hydrogen atom of specific energy, the number of states depends on the angular momentum. The total energy depends on the principal quantum.
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17. Given: CuSO
KlCul_K50)
Answer the following:
a. Determine the limiting reactant when 6.76 grams of copper(II) sulfate is reacted with 9.82
grams of potassium iodide?
b. Using the information from (a), what would be the mass of all three products?
C.
If 0.331 grams of iodine is produced, how many molecules of KI were reacted?
I think its c. I'm not 100% tho
An isotope has an atomic number of 36 and contains 44 neutrons. What is the isotope’s mass number?
the isotopes mass number is 36
Explanation:
because atomic number is also mass number
What is Electron gain Enthalpy?
Answer:
Electron gain enthalpy is defined as the amount of energy released when an electron is added to an isolated gaseous atom.
Some lipid rafts are characterized by an accumulation of cholesterol. What does this mean for the fluidity of the lipid raft?.
The lipid rafts are less fluid than the surrounding membrane at normal temperatures.
Cholesterol decreases the fluidity of the membrane at normal temperatures.
Lipid rafts regulate neurotransmission, receptor traffickinging and influence membrane fluidity.
Membrane fluidity refers to the viscosity of the lipid bilayer.
Cholesterol in the rafts has a potential to effectively control the ion conductance and excitability of membranes.
For example, in phospholipid layer in cell membrane, there are hydrophilic heads (polar part of the layer) and hydrophobic tails (nonpolar part of the layer).
1) Small, non-polar molecules diffuse easily through this layer, no energy is required, this is passive transport.
2) Polar molecules cannot diffuse through phospholipid layer using passive transport, because hydrophobic tails does not allow that (polar molecules are reppeled), energy is required for that, this is active transport.
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Two or more substances in variable proportions where the composition is constant throughout are.
Answer:
homogenous mixture
Explanation:
no choices are given so that is my best guess
BEERS LAW - EASY - Use this method to calculate the molar concentration of "copper (II) sulfate" if it has a measured absorbance of 2.17. The absorbance of a 0.10 M solution is 0.96. Round your answer to correct significant figures and do not include units.
The molar concentration of copper (II) sulfate that has a measured absorbance of 2.17 is 0.23 M.
What is the concentration of the copper (II) sulfate" if it has a measured absorbance of 2.17?
The concentration of the copper (II) sulfate that has a measured absorbance of 2.17 is determined by the Lambert-Beer's law which is given below as follows:
A = ε * l * cwhere:
A = absorbance measured by the spectrometerε = molar absorptivity,l = path length of light through the cellc= concentration, in mol/L, of the sample solution being measuredSince the values of molar absorptivity and path length are constant, the Lambert-Beer's law can be expressed as follows:
A₁/C₁ = A₂/C₂
Where A₁ is absorption at concentration C₁
A₂ is absorption at concentration C₂
From the data provided:
A₁ = 0.96
C₁ = 0.10
A₂ = 2.17
C₂ = ?
C₂ = A₂ * C₁/A₁
C₂ = 2.17 * 0.1/0.96
C₂ = 0.23
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