1.54 × 10²⁴ atoms He
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
MolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 2.56 moles He
[Solve] atoms He
Step 2: Identify Conversion
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 2.56 \ mol \ He(\frac{6.022 \cdot 10^{23} \ atoms \ He}{1 \ mol \ He})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 1.54163 \cdot 10^{24} \ atoms \ He[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.54163 × 10²⁴ atoms He ≈ 1.54 × 10²⁴ atoms He
Which of the following are true about an atom? Choose all that apply.
Answer:
Explanation:
Atoms are the building blocks of matter.
They are the smallest particles of an element that still have the element's properties.
All atoms are very small, but atoms of different elements vary in size.
Three main types of particles that make up all atoms are protons, neutrons, and electrons.
19. 1 mole = _____________________ _________________ g
Answer:
344.1g
Explanation:
Which gland in the human body is a part of two human body systems (Digestive &
Endocrine)?
A. Testes
B. Ovaries
C. Both
D. Pancreas
Answer: D pancreas
Explanation: testes are for male ovary are for female one human can have both
Kinematics equations are used only by physicists and people who work in
space.
A. True
B. False
Answer:
FALSE
Explanation:
false. kinematics equations are used for many purposes.it is used to drive equations and to find the motion of an object. but it is used more in physics rather than maths.
03
A force of 20 N acts upon a 5 kg block. Calculate the acceleration of the object.
The breakdown of a certain pollutant X in sunlight is known to follow first-order kinetics. An atmospheric scientist studying the process fills a 20.0Lreaction flask with a sample of urban air and finds that the partial pressure of X in the flask decreases from 0.473atm to 0.376atm over 5.6hours.
Calculate the initial rate of decomposition of X, that is, the rate at which Xwas disappearing at the start of the experiment.
Round your answer to 2 significant digits.
Answer:
0.019 atm / hr
Explanation:
Initial Concentration (Pressure) [A]o = 0.473 atm
Final Concentration (Pressure) [A] = 0.376 atm
Time = 5.6 hours
The breakdown follows first order kinetics.
The integrated rate law for a first order reaction is given as;
ln[A] = ln[A]o - kt
ln(0.376) = ln(0.473) - k (5.6)
ln(0.376) - ln(0.473) = - 5.6 k
5.6 k = 0.23
k = 0.0411 hr⁻¹
The rate of decomposition is given as;
Rate = k [X]
Where [X] represents Concentration (Pressure) = 0.473 atm
Rate = 0.0411 * 0.473 = 0.019 atm / hr
Am I correct?
As gravity/distance increases between two objects, the gravitational pull between them weakens/strengthens
Yes, As the gravity/distance increases between two objects, the gravitational pull between them weakens/strengthens.
Explanation:There is a gravitational force of attraction between every object in the universe. The size of the gravitational force is proportional to the masses of the objects and weakens as the distance between them increases.
Is nitric acid a strong or weak acid. Explain your answer.
Answer:
Examples of strong acids are hydrochloric acid (HCl), perchloric acid (HClO4), nitric acid (HNO3) and sulfuric acid (H2SO4). A weak acid is only partially dissociated, with both the undissociated acid and its dissociation products being present, in solution, in equilibrium with each other.
Explanation:
Hope this helps you
This is the chemical formula for Chormium (III) nitrate Cr(NO3)3Calculate the mass percent of nitrogen in chromium(III) nitrate.
Answer:
The percent composition for nitrogen in chromium(III) nitrate is 6%.
Explanation:
The mass percent of nitrogen in chromium(III) nitrate is 17.655%.
Calculation,
Molar mass of one oxygen = 16 g
molar mass of nine oxygen = 9 × 16 g = 144 g
molar mass of one nitrogen atom = 14 g
molar mass of three nitrogen atom = 3 × 14 g = 42 g
molar mass of one chromium atom = 51.99 g
molar mass of chromium (III) nitrate molecule = 144 g + 42 g + 51.99 g = 237.99 g
Mass percent of nitrogen = mass of three nitrogen atom× 100 /mass of chromium(III)nitrate
Mass percent of nitrogen = 42 g/237.99 g × 100 = 17.655%
What is mass percentage?The percentage of the mass of the element or solute divided by the mass of the compound or solute is called mass percentage
learn about mass percentage,
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Jane is sitting in the family car. Her mother is driving her from their house to the library. Jane waves as she passes her friend Marina. Which of the following is not moving with respect to Jane?
A. Marina
B. The family car
C.The library
D. Jane’s house
Answer:
B) The family car
Explanation:
I hope this helps :)
Question 2 2 points)
Which of the atoms shown has an atomic number of 42
1
2
4
7
Answer:
4 is the answer
Explanation:
i am not sure for this question
Which of the following statements correctly explain the relationship between the solubility of a gas and its pressure?
A. As pressure is increased, the rate at which gas molecules enter the solution decreases.
B. More gas molecules are soluble as pressure is increased.
C. The solubility of a gas decreases with a decrease in pressure.
D. The solubility of nitrogen gas at 2.00 atmatm is twice the solubility of the gas at 1.00 atmatm.
E. The concentration of gas particles in the solution is higher at 4.25 atmatm than at 1.00 atmatm.
F. Fewer gas molecules are soluble at higher pressures.
G. As pressure decreases, the concentration of gas molecules in the solution increases.
Answer:
B, C, D, E
Explanation:
According to Henry's law, as the pressure is increased, the solubility of a given gas increases. So, solubility is directly proportional to pressure.
Thus, the following statements are correct:
B. More gas molecules are soluble as pressure is increased.
Is correct because as the pressure is increased, the solubility increases.
C. The solubility of a gas decreases with a decrease in pressure.
Is correct because solubility and pressure are directly proportional: if the pressure is decreased, the solubility will be decreased.
D. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm.
Is correct because 2.00 atm is twice 1.00 atm, so if the pressure is increased twice, the solubility is increased twice.
E. The concentration of gas particles in the solution is higher at 4.25 atm than at 1.00 atm.
Is correct because 4.25 atm>1.00 atm (the higher the pressure, the higher the solubility, and therefore the concentration of gas particles in solution).
The remaining options (A, G) are incorrect. They contradict Henry's law.
A sample of NH3(g) is placed in a rigid container. When the equilibrium below is established, the partial pressure of hydrogen gas is 0.978 atm. What is the partial pressure of N2(g) at equilibrium?
Answer:
PpN₂ = 0.326 atm
Explanation:
In this case, let's write the equilibrium reaction taking place here:
2NH₃(g) <------> 3H₂(g) + N₂(g)
Now, we know that when the reaction reach the equilibrium the partial pressure of H₂ is 0.978 atm, so, let's write an ICE chart and see what's happening here:
2NH₃(g) <------> 3H₂(g) + N₂(g)
i) y 0 0
c) -2x +3x x
e) y-2x 3x x
At the beggining we just have the sample of NH₃, we don't know how much but we don't need that data to get the partial pressure. In equilibrium, its produced hydrogen and nitrogen, and we know how much of hydrogen was produced, so, with that we can solve for the value of the partial pressure of NO by a simple math operation:
PpH₂ = 0.978 atm = 3x
PpN₂ = x
PpN₂ = PpH₂ / 3
PpN₂ = 0.978 / 3
PpN₂ = 0.326 atmHope this helps
Oxygen and hydrogen are both elements that are found as gases at room temperature. When oxygen combines with hydrogen, they produce the compound water according to the chemical equation below.
O2 + 2 H2 2 H2O
Water is a liquid at room temperature. This example shows that in a chemical equation, the substance that is produced
A.
has properties that are different from the original substances.
B.
can only contain a single type of element.
C.
contains fewer types of elements than the original substances.
D.
always has the same properties as the original substances.
Answer:
A
Explanation:
has properties that are different from the original substances.
Explain the 3 steps required to determine the molecular formula.
Answer:
The steps involved in determining a Molecular Formula are: Find the mass of the empirical formula. Divide the molecular mass by the mass of the empirical formula. Multiply each subscript in the empirical formula by the answer.
Explanation:
What is the density of nitrogen gas at 356.4 K?
Answer:
Nitrogen gas (chemical symbol N) is generally inert, nonmetallic, colorless, odorless and tasteless. Its atomic number is 7, and it has an atomic weight of 14.0067. Nitrogen has a density of 1.251 grams/liter at 0 C and a specific gravity of 0.96737, making it slightly lighter than air.
Explanation:
:)
tion 7
In the beginning of the reaction, A B+C, 2 moles of A are taken, out of which 0.5 moles
gets dissociated. What is the amount of dissociation of A?
(1) 0.5
(2) 1
(3) 0.25
(4) 4.2
can someone please help me asap ill mark u brainlest
Answer:It is the ground state of NA
Which food dyes in the diagram on the right only contain one colour?
( Science, Chromatography )
Rocks are classified on the basis of
Answer:
Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size. This transformation produces three general classes of rock: igneous, sedimentary and metamorphic. Those three classes are subdivided into many groups.
Explanation:
AlCl3(s)+Ca3N2(s)→AlN(s)+CaCl2(s)
Answer:
the subject of a talk, piece of writing, exhibition, etc.; a topic.
Explanation:
Answer:
1 NH4NO3(s) → 1 N2(g) + 4 H2O(g) + 2 O2(g)
Explanation:
escape room ocean and air currents. Escape room
Answer:
1683
Explanation:
i did that game a few weeks ago preeeettyyyyyyyy sure that's the right number
What are two ways to determine the salinity level?
Answer: chlorinity titration and conductometry
Explanation:
Answer these questions. What are metals? Write the position of alkali metals and alkaline earth metals in the modern periodic table.
Explanation:
a metal is an element that readily forms positive ions (cations) and has metallic bonds.
Group two of the periodic table comprises the elements beryllium, magnesium, calcium, strontium, barium and radium. The elements in this group, which are all shiny and silvery-white in appearance, are known as the alkaline earth metals. Like the alkali metals, they form alkaline solutions when they react with water.
Guys i need help because its due today.
Answer:
204.6 K
Explanation:
PV = nRT
5.6 (12) = 4 (.0821)T
67.2 = .3284T
204.6 = T
Move the red warning icon to focus of the earthquake.
Move the green location icon to the epicenter of the earthquake.
Move the blue star icon to the fault.
Answer:
Red goes in the spiky yellow box. Green goes where the red circles are. Blue goes in the small yellow box that is pointing to the line.
Explanation:
The focus of an earthquake is where it starts in the earth. The epicenter is the part directly above the focus on the surface. The fault is the part where the earth's crust splits.
Where did the magma and sediment that formed the rock of the Great Plains and the Rocky
Mountains come from?
Which claim do you think is more likely to be true?
Claim 1: The sediment that formed the Great Plains came from the rock of the Rocky
Mountains.
Claim 2: The magma that formed the Rocky Mountains came from the rock of the Great Plains.
Answer:
1
Explanation seems right
The magma and sediments formed in the great plains are came from the rocks of the rocky mountains. Therefore, claim 1 is correct.
What is sedimentation?Sedimentation is the geographical process of accumulation or deposition of the minerals and organic particles from the earth's surface is called sedimentation. This process results in the formation of sedimentary rocks.
Weathering or erosion of rocks by wind, water or other chemicals leads to the geological debris which then move to other places deposits somewhere.
Rocks in the rocky mountains undergo erosion and the mass movements created by wind or water leads to the sedimentation of these rocky solids to other places. The rocks in the Great planes are reached there by the mass movement of the rocks of rocky mountains. Hence, claim 1 is correct.
To find more on sedimentation, refer here:
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Both magnetic fields and electric fields can exert a force true or false?
Answer:
false
Explanation:
An electric field may do work on a charged particle, while a magnetic field does no work.
The element sulfur (S) is most likely to form covalent bonds with the element
helium (He).
magnesium (Mg).
zinc (Zn).
oxygen (O).
The element sulfur (S) is most likely to form covalent bonds with the element oxygen. Thus, the correct option for this question is D.
What do you mean by Covalent bonds?Covalent bonds may be defined as a type of chemical bond that significantly involves the mutual sharing of electrons in order to form electron pairs between atoms. This pairing of electrons is simultaneously attracted by the two atomic nuclei.
Sulfur is categorized into the category of nonmetal in group 6A, and therefore it has 6 valence electrons. In order to obey the octet rule, it needs to gain 2 electrons. It can do this by forming 2 single covalent bonds.
The sulfur atom subsequently shares four valence electrons with two oxygen atoms as two covalent double bonds, and shares its remaining two electrons with two oxygen atoms, forming two covalent single bonds.
Therefore, the element sulfur (S) is most likely to form covalent bonds with the element oxygen. Thus, the correct option for this question is D.
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Every orbital in a sub level is singly occupied before any orbital is doubly occupied is the statement of
Answer:
Hund's rule of maximum multiplicity