Answer:
A
Explanation:
Before the student left, the water molecules were moving in place, then after that, the water molecules were moving around each other.
Option A is correct.
Water can exist in three phases of matter as solid, liquid, or gas. In the solid state, the constituent of the particles is closely packed together.
In the liquid state, the particles are held together by intermolecular forces and they move around each other.In the solid state, before the student left the sealed jar outside her house, the particles molecules of the water are moving in place closely packed together, but after a period of time, the molecules start to move around each other.
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How many significant figures are there in 8.280?
Answer:
number of significant figures-4
number of decimals-3
According to the passage, how does conserving energy helps combat climate change?
A
It turns off the lights automatically.
B
It reduces the need for fossil fuels.
C
It recycles old materials into new ones.
D
It releases greenhouse gasses into the air.
Answer:
B it reduces the need for fossil fuels
Explanation:
I got the answer wrong and it showed B was the right one
What is the molarity of a solution that has 2.52 grams of NaCO3 dissolved to
make 0.125 Liters of solution?
Answer:
Explanation:
2.52g/ 0.125L= 20.16M
How many particles are in 1.43 g of a compound with a molar mass of 233? (No molar mass calculation needed) (show work plz)
Answer:
Explanation:
mol = given mols / molar mass
given mass = 1.43 grams
molar mass = 233
mols = 1.43 / 233 = 0.00614
1 mol contains 6.02 * 10^23 particles
0.00614 moles = x Cross multiply
1*x = 0.00614 * 6.02*10^23
x = 3,68 * 10^21 particles.
What is the molarity when 1.25 mol is dissolved in 3.50 L of solution?
Answer:
0.36 mol/L
Explanation:
The formula for molarity M=m/L
m stands for moles
L stands for liters
Plug it into the equation...
M=1.25 mol/3.5 L
M=0.35714285714
Form hypothesis: Which factor(s) do you think determine whether the car breaks the egg?
The mass of the car only _____
The kinetic energy of the car ____
The speed of the car only ___
The momentum of the car ___
(GIZMOS)
Part I: Multiple Choice Questlons
1. A solution is a:
a heterogeneous mixture
C suspension
b homogeneous mixture
d colloid
Answer:
A cuz a heterogeneous mixture is no uniform
Answer:
A heterogeneous mixture
WS Percent yield don’t understand how to do would appreciate the help
Answer:
1. Theoretical yield of NaOH is 22.72 g
2. Percentage yield of NaOH = 22.14%
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
NaHCO₃ —> NaOH + CO₂
From the balanced equation above,,
1 mole of NaHCO₃ decomposed to produce 1 mole (i.e 40 g) of NaOH and 1 mole (i.e 44.01 g) of CO₂.
Next, we shall determine the number of mole of NaHCO₃ that will decompose to produce 25 g of CO₂. This can be obtained as follow:
From the balanced equation above,,
1 mole of NaHCO₃ decomposed to produce 44.01 g of CO₂.
Therefore, Xmol of NaHCO₃ will decompose to 25 g of CO₂ i.e
Xmol of NaHCO₃ = 25 / 44.01
Xmol of NaHCO₃ = 0.568 mole
1. Determination of the theoretical yield of NaOH.
From the balanced equation above,,
1 mole of NaHCO₃ decomposed to produce 40 g of NaOH.
Therefore, 0.568 mole of NaHCO₃ will decompose to produce = 0.568 × 40 = 22.72 g of NaOH.
Thus, the theoretical yield of NaOH is 22.72 g
2. Determination of the percentage yield of NaOH.
Theoretical yield of NaOH = 22.72 g
Actual yield of NaOH = 5.03 g
Percentage yield of NaOH =?
Percentage yield = Actual yield /Theoretical yield × 100
Percentage yield = 5.03 / 22.72 × 100
Percentage yield of NaOH = 22.14%
When a warm air mass is trapped between two (2) cold air masses, the result is a(n)?
Answer:
results in a Occluded front
a category of classification below a kingdom? A phylum B domain C species
Answer:
Phylum
Explanation:
After that it goes class, order, family, genus, and finally species. In that order, BTW before kingdom is domain.
Answer:
Phylum
Explanation:
 how are subscripts determine the formula of ionic and covalent compounds ?
Answer:
To determine the correct subscripts in a chemical formula, you have to solve how many atoms you need to balance the charge.
For example if I had the compound Calcium Fluoride I would look at the periodic table and see that Calcium's ionic formula is
Ca2+
. How do I know this? Well all elements want to have 8 valance electrons so they can be stable(happy). Seeing that Calcium has 2 valance electrons it is going to give away 2 electrons because that is easier than gaining 6 to be happy. Since Calcium has given away 2 electrons it has two more protons than electrons. We know that Protons have a Positive charge, Electrons have Negative charge, and the number of electrons is equal to the atomic number of an element in its pure non-ionic state. (Meaning it doesn't have a positive or negative charge; it is balanced.)
So if calcium gave away two electrons, it will have two more protons than an electron giving it a (2+) charge. The same process can be applied to Fluoride. Since fluoride is one to the left of the noble gases(group 18 or 8A) on the periodic table we know that it has 7 valance electrons because it is in group 7A or 17.
Knowing that we have 7 electrons the fluoride atom will gain an extra electron. Since the fluoride atom gained an extra electron it will have one more negative charge than a positive making it a ^(−)ion.
So you know that Calcium has a 2+ charge and that fluoride has a 1- charge, you then need these ions to balance out. So you need two fluorine atoms with a 1- ions to balance out the 2+ ion of calcium. Your final answer would be
CaF2
because you need two fluorine atoms to balance out the 2+ charge of the calcium.
Final Tip: Determine the charges then inverse the charges, remove the positive and negative superscipts, and write the charge numbers as a sub script. Ie. Calcium Fluoride
Ca2+ and F−
inversing and removing the charge signs would give you
if you have 58 g of Copper what is the mass of Silver nitrate?
____Cu +____AgNO3 →
____Ag+ ____Cu(NO3)2
Answer:
Add 2 to Cu in first part of problem only
ASAP!! How many moles are in 125 g of H2SO4
Answer:
1.276 moles
Explanation:
molar mass of H2SO4 = 2(1)+(32)+4(16) = 98 g
So, there are (125g)(1 mol/98g) = 1.276 moles
1.276 moles are in 125 g of H[tex]_2[/tex]SO[tex]_4[/tex]. A mole is indeed a unit that enables us to correlate the mass of a material with its components.
What is mole?It is defined as the amount of any material that has the same number of basic units as there are in a precisely measured sample of 12C that weighs 12 g. Latin's word for pile, stack, or assemblage is "mole." The number of entities that make up a mole was discovered via experimentation to be 6.022 X 1023.
A mole is indeed a unit that enables us to correlate the mass of a material with its components. The total of the masses of all the atoms that make up one mole of a molecule, expressed in grams, is what is known also as molecular mass or molar mass. A substance's molar mass may be calculated by multiplying its given mass by its g/mol density.
molar mass of H[tex]_2[/tex]SO[tex]_4[/tex] = 2(1)+(32)+4(16)
= 98 g
mole= (125g)(1 mol/98g)
= 1.276 moles
Therefore, 1.276 moles are in 125 g of H[tex]_2[/tex]SO[tex]_4[/tex].
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A metal atom loses electrons from its outermost energy level and acquires a
charge. These electrons join a nonmetal atom. The ionic compound formed because of this transfer of electrons is electrically
.
Answer:
Answer : A metal atom loses electrons from its outermost energy level and acquires a Positive Charge. These electrons join a nonmetal atom. The ionic compound formed because of this transfer of electrons is electrically Neutral.
Explanation or losing electrons. For metals, the number of valence electrons are less and it is easier to lose these electrons.
When electrons are lost, the number of protons become more than the electrons. This creates an excess of positive charge. As a result the species becomes positively charged and is known as cation.
During formation of ionic bond, metals always form a positive ion (cation) by losing electrons. These electrons are accepted by the nonmetals and they become negatively charged. A negatively charged ion is known as anion and nonmetals always form an anion.
These are attracted to each other due to the opposite charges present on them. In an ionic compound they balance the charges on each other making the compound neutral.
From the above discussion, we can fill in the blanks as follows.
A metal atom loses electrons from its outermost energy level and acquires a Positive Charge. These electrons join a nonmetal atom. The ionic compound formed because of this transfer of electrons is electrically Neutral.
Most caves form in: *
O Igneous rock
O Compacted soil
O Limestone
Sandstone
Oxygen and chlorine gas are mixed in a container with partial pressure of 401 mmHg and 0.639 atm Respectively. What is the total pressure inside the container?
How many moles of carbon tetrabromide are present in 5. 27x10`22 molecules of the compound
Answer: 0.094 mole
Explanation: same answer for any molecule, actually.
6.02214076*10^23 per mole
5.7*10^22 = 0.094 mole
What is Magnesium phosphide cation and Anion
Answer:
Magnesium Phosphide has a formula of Mg3P2 . Magnesium is a metal cation with a charge of Mg+2. Phosphorus is a nonmetal anion with a charge of P−3. In order to bond ionically the charges must be equal and opposite
Explanation:
Calculate the number of molecules in
3.7 x 10-2 Liters of oxygen gas at STP. Round your answer to the nearest whole number.
9.9 × 10²⁰ molecules O₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc. STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 KStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
3.7 × 10⁻² L O₂ at STP
Step 2: Identify Conversions
[STP] 22.4 L/mol
Avogadro's Number
Step 3: Convert
Set up: [tex]\displaystyle 3.7 \cdot 10^{-2} \ L \ O_2(\frac{1 \ mol \ O_2}{22.4 \ L \ O_2 \ at \ STP})(\frac{6.022 \cdot 10^{23} \ molecules \ O_2}{1 \ mol \ O_2})[/tex]Multiply/Divide: [tex]\displaystyle 9.94705 \cdot 10^{20} \ molecules \ O_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
9.94705 × 10²⁰ molecules O₂ ≈ 9.9 × 10²⁰ molecules O₂
a phosphorus ion with a charge of -2 has ____ protons ____ neutrons,and _____ electrons
The number of protons of an atom is always equal to the atomic number of the atom's element. In this case, we can assume that a phosphorus ion is simply an atom of phosphorus that is an ion, i.e., an atom with a nonzero electric charge. To refresh, there are three key subatomic particles that make up an atom: protons (which have a positive charge), neutrons (which have no electric charge), and electrons (which have a negative charge). Protons and neutrons are found bound to each other in the nucleus (an exception would be a neutral hydrogen, ¹H, atom, whose nucleus comprises only a single proton and no neutrons).
The atomic number of phosphorus is 15. Therefore, the phosphorus ion has 15 protons.
The number of neutrons in a phosphorus atom can be calculated by subtracting the atomic number from the atomic weight. The atomic weight of phosphorus is approximately 30.974 amu (the decimals come from the fact that this value is a weighted average of the masses of naturally-occurring isotopes of phosphorus). For our purposes, we can round our atomic weight to 31, which would reflect the number of protons and neutrons in a phosphorus atom. Subtracting our 15 protons from 31 gives us 16 neutrons. Since neutrons have no electric charge, their number would be the same in both a neutral atom and an ion of a particular isotope of phosphorus. Since we're presumably working with ³¹P (which is by far the most abundant isotope), we can safely say that the phosphorus ion has 16 neutrons.
Recall that protons have a positive charge, and we've just reiterated that neutrons have no electric charge. If all that made up an atom were protons and neutrons, the atom would have a net positive charge due to the protons. A neutral atom of an element, by definition, has no net charge because of the negatively-charged electrons surrounding the positively-charged nucleus. It follows, then, that in a neutral atom, the number of electrons equals the number of protons; so, in a neutral phosphorus atom, there would be 15 protons, 16 neutrons, and 15 electrons. The 15 positively-charged protons would neutralize the 15 negatively-charged electrons, resulting in a net atomic charge of 0.
In our phosphorus ion, we have a net charge of -2. That means that, given a nucleus with 15 positively-charged protons, we have an imbalance of 2 more negative charges. 15 electrons are needed to maintain an electrically neutral phosphorus atom; for each electron that is removed, the atom gains a positive charge, and for each electron that is added, the atom gains a negative charge. Since we have a -2 charge in the phosphorus ion, there must be 2 electrons in addition to the 15 electrons found in a neutral phosphorus atom, or 17 electrons in total. Therefore, the phosphorus ion has 17 electrons.
Note: A positively-charged ion is also called a cation, and a negatively charged ion is also called an anion. The charge of an ion has the general form Xⁿ⁺ or Xⁿ⁻, where X is the chemical species (such as an element), n is the magnitude of the charge, and the + or - respective denote a net positive or negative charge. In this case, one could represent the phosphorus anion as P²⁻.
A phosphorus ion with a charge of -2 has 15 protons, 16 neutrons, and 18 electrons.
The atomic number of phosphorus is 15, which means it naturally has 15 protons in its nucleus. Since the ion has a charge of -2, it means it has gained two extra electrons.
The number of protons remains the same in an ion, so it still has 15 protons. However, the number of electrons changes to accommodate the charge. The ion possesses 15 protons and 17 electrons because it has a -2 charge.
To calculate neutrons, subtract 15 from phosphorous' mass number. The neutron count for phosphorus is 31 - 15 = 16. Thus, a -2 phosphorus ion contains 15 protons, 16 neutrons, and 18 electrons.
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How many electrons does potassium have in its outside electron shell?
Answer:
Potassium (K) is of atomic number 19 and has only 1 electron in the outermost shell
And this is because of the octet rule of chemistry followed while determining the number of electrons in each shell.
According to the octet rule, there can only be a maximum of 8 electrons in the outer shell of an atom, So when 'L' shell of K is filled with 8 electrons to accommodate the 19th electron a new shell will be created
Which of the following statement is true how fossil records can produce incomplete evidence of organisms that lived on Earth?
Small plants and animals found on Earth were not fossilized.
Not all organisms that lived on Earth have been fossilized.
Large plants and animals found on Earth were not fossilized.
There are fossils that we cannot identify.
Answer
i think b
they making me put 20 characters so dont mind what you reading lol
determine the empirical and molecular formulas of a compound that gives the following analysis in math percent: 24.27% C,4.07% H, and 71.65%CL. the molar mass is known to be 197.92g/mol.
Answer:
help me with this
Explanation:
Carbon is the most abundant element in the universe.
O True
O False
Answer:
Carbon is not only the most abundant element on Earth; it is believed to be the most abundant element in the universe. Each of carbon's three valence electrons shares a bond with another atom. Single bonds between carbon atoms are typically shorter than double bonds between carbon atoms.
Explanation:
Answer:
False
Explanation:
pls help
Plot the point (5,9)
Describe why there are places on the curve where the temperature does not rise even though the burner is stil transferring energy to the ice and water.
Answer:
y
Explanation:
Atom X contains nine protons and seven neutrons. Atom Z contains nine protons and eight neutrons. Which of the following statements correctly describes the two atoms? (AKS 1a/DOK 1)
A.
They have the same mass number
B.
They are radioactive
C.
They are isotopes
D.
They are atoms of different elements
30. The density of an unknown gas at 27°C and 2 atm pressure is equal with density of N2 gas at
52°C and at 5 atm
pressure. Calculate the molar mass of that unknown gas.
pls help guys
Answer:
Molar mass of the unknown gas is 64.6 g/mol
Explanation:
Let's think this excersise with the Ideal Gases Law.
We start from the N₂. At STP conditions we know that 1 mol of anything occupies 22.4L.
We apply: P . V = n . R . T
5 atm . V = 1 mol . 0.082 . 325K
V = (1 mol . 0.082 . 325K) / 5 atm = 5.33 L
It is reasonable to say that, if we have more pressure, we may have less volume.
As this is the volume for 1 mol of N₂, our mass is 28 g. Then, the density of the nitrogen and the unknown gas is 28 g/5.33L = 5.25 g/L
Our unknown gas has, this density at 27°C and 2 atm.
If we star from this, again: 1 mol of any gas occupy 22.4L at STP, we can calculate the volume for 1 mol at those conditions:
P₁ . V₁ / T₁ = P₂ . V₂ / T₂
1 atm . 22,4L / 273K = 2 atm . V₂ / 300K
Remember that the value for T° is Absolute (T°C + 273)
[ (1 atm . 22.4L / 273K) . 300K] / 2 atm = V₂ → 12.3L
This is the volume for 1 mol of the unknown gas at 2 atm and 27°C
We use density to determine the mass: 12.3 L . 5.25 g/L = 64.6 g
That's the molar mass: 64.6 g/mol
Decide which element probably forms a compound with chlorine that has a chemical formula most and least similar to the chemical formula of the compound formed by chlorine and rubidium. Comparing chemical formula of compound formed with chlorine: phosphorus beryllium magnesium lithium most similar to rubidium least similar to rubidium
Answer:
Most similar - Lithium
Least similar - Phosphorus
Explanation:
Rubidium is an element in group 1A of the periodic table. It is a metal and forms an ionic compound with chlorine. The formula of the compound is RbCl.
If we look at the options, Lithium is also a group 1A element and forms an ionic compound with chlorine having the formula LiCl which is very much similar to RbCl chemically.
Phosphorus is a nonmetal. Its compounds with chlorine, PCl3 and PCl5 are covalent and does not resemble RbCl in any way.
A chemical reaction produces 138 mol of HBr gas. What volume will that gas occupy at STP?
3.09E3 L
3.09E4L
22.4L
3.25E2L
The chemical reaction at STP results in a volume of HBr gas that is roughly 3.09E3 L.
An example of a chemical reactionIn a chemical reaction, reactants undergo a chemical reaction and transform into products through a chemical process. For instance, when humans breathe in oxygen, it combines with glucose to create carbon dioxide, water, and energy.
The temperature is 273.15 K and the pressure is 1 atm at STP (standard temperature and pressure).
The ideal gas law can be rearranged to account for V:
V = (nRT) / P
Substituting the values we are aware of:
n = 138 mol
R = 0.0821 L·atm/(mol·K)
T = 273.15 K
P = 1 atm
V = (138 mol * 0.0821 L·atm/(mol·K) * 273.15 K) / 1 atm
V = 3,092.1 L
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