The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element. The atomic number uniquely identifies a chemical element. It is identical to the charge number of the nucleus. In an uncharged atom, the atomic number is also equal to the number of electrons.
Answer:
its basically represents the number of protons in the nucleus which in a neutral atom equals the number of electrons outside the nucleus and that determines the place of the element in the periodic table
Explanation:
sry i its too long
hope it helps
A 4.00g sample of helium has a volume of 24.4L at a temperature of 25.0 C and a pressure of 1.00 atm. The volume of the helium is reduced to 10.4L, but the temperature and pressure of the gas are kept constant. What is the new quantity of the gas in moles
Answer:
0.852 mol
Explanation:
First we convert 4.00 g of helium (He) into moles, using its molar mass:
4.00 g ÷ 2 g/mol = 2 mol He
To answer this problem we can use Avogadro's law, which states that at constant pressure and temperature:
V₁n₂=V₂n₁
Where:
V₁ = 24. 4 Ln₂ = ?V₂ = 10.4 Ln₁ = 2 molWe input the data:
24.4 L * n₂ = 10.4 L * 2 molAnd solve for n₂:
n₂ = 0.852 mol
What's the Molar Mass of O2?
O 16.0 g/mole
o 32.0 g/mole
1.0 g/mole
O 2.0 g/mole
Zach invited his friend Sydney to a pool party over the weekend. Sydney informed Zach that the climate was supposed to be rainy over the weekend and suggested that he change his plans. Zach explained to Sydney that she had misused the word “climate” and she should have used the word “weather” instead. Which of the following statements accurately clarifies the confusion between Zach and Sydney?
A). Zach is correct; the weather for this area is typically tropical and wet.
B). Sydney is correct; there has been an abundance of rainfall within the last month, changing the climate of this particular area.
C). Zach is correct; the climate of an environment is determined by patterns in weather conditions over an extended period of time.
D). Sydney is correct; the climate of an environment can change constantly based on weather, wind, and front patterns in the area.
Answer:
C
Explanation:
Common sense
Which term goes hand in hand with biodiversity?
(A.) sustainability
(B.) competition
(C.) survival
(D.) homeostasis
The Concrete that surrounds a swimming pool takes less time to heat up than the water in the pool. Why
Answer:
The Concrete has a lower specific heat.
Explanation:
What is the molarity of a solution containing 52.6g of NaOH dissolved in 2.5L of water?
Answer:
Molarity = no of moles of solute/volume of solution in litre
number of moles =given mass/molar mass
moles= 50.6/40 = 1.315 moles
now,
molarity = 1.315/2.5= 0.526M
A student prepares four different aqueous NaCl solutions according to the table. Which solution will have the highest molarity?
Brainly is erroneously blocking my answer from being posted due to nonexistent profanity and/or links, so I have attached an image of my written response. Please let me know if you have any problems seeing it.
you have a gas that has a pressure of 2 atm and a volume of 10L. what would be the new volume if the pressure was changed to 1atm?
Answer:
20 Liters
Explanation:
Boyles Law => ΔP ∝ 1/ΔT => P₁V₁ = P₂V₂ => V₂ = P₁V₁/P₂
P₁ = 2 atm
V₁ = 10 Liters
P₂ = 1 atm
V₂ = ?
V₂ = 2atm x 10L / 1atm = 20 Liters
An unknown amount of Al203 decomposed producing 215 g of solid aluminum. 2Al2O3=4Al+3O2 How many grams of oxygen gas should be produced
Answer:
191.11 grams of oxygen gas should be produced.
Explanation:
The balanced reaction is:
2 Al₂O₃ → 4 Al + 3 O₂
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
Al₂O₃: 2 molesAl: 4 molesO₂: 3 molesBeing the molar mass of each compound:
Al₂O₃: 102 g/moleAl: 27 g/moleO₂: 32 g/moleBy reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
Al₂O₃: 2 moles* 102 g/mole= 204 gramsAl: 4 moles* 27 g/mole= 108 gramsO₂: 3 moles* 32 g/mole= 96 gramsThen you can apply the following rule of three: if by stoichiometry 108 grams of aluminum are produced along with 96 grams of oxygen, 215 grams of aluminum are produced along with how much mass of oxygen?
[tex]mass of oxygen=\frac{215 grams of aluminum*96 grams of oxygen}{108grams of aluminum}[/tex]
mass of oxygen= 191.11 grams
191.11 grams of oxygen gas should be produced.
Calculate the mass in grams of 2.56 × 10 −3 mol of iron.
Answer:
1.43 grams
Explanation:
Fe = 55.8 grams Fe = 1 mole Fe
2.56 • 10^-3 moles Fe / 1 • 55.8 grams Fe / 1 mole Fe = 1.43 grams Fe
Basically, you're just multiplying the molar mass of Fe (iron) by the moles of 2.56 • 10^-3 Fe, to find how many grams are in it.
2.56 • 10^-3 moles Fe = 1.43 grams Fe
How can the strength of an acid be determined using titration? (100 POINTS!)
Answer:
Explanation:
A titration in general is used to determine the concentration of something with a solution of known solution. For acid, a base solution of known concentration is added slowly. The end-point is determined by using a pH indicator. When the acid is neutralized at the end, note the amount of base solution used and the strength of acid can be calculated.
Note that the quantity of base solution utilised and the acid strength can be estimated after the acid has been neutralised.
What is titration?Titration is a method of chemical analysis where the quantity of a sample's constituents is established by adding a precisely measured amount of something else with which the component that is wanted will react in a specific, known proportion.
A burette, which is essentially a long, graded measurement tube with a stopper and a tube for injection at its bottom end, is used to gradually administer a standard solution of titrating reagent, and titrant, to a specified concentration. When the point of equal value is achieved, the addition is terminated. Note that the quantity of base solution utilised and the acid strength can be estimated after the acid has been neutralised.
Therefore, note that the quantity of base solution utilised and the acid strength can be estimated after the acid has been neutralised.
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When two objects come in contact with each other, friction occurs and
a
both objects change directions
b
both objects will receive a certain amount of thermal energy and heat up
c
one object will heat up while the other cools down
d
both objects immediately cool down to room temperature
Answer:
b
both objects will receive a certain amount of thermal energy and heat up
uh id.k how to fill this out, i mean the type of reaction part is obvious but id.k what to put in the box and the other blue part.
Answer:
Explanation:
Strontium chlorate appears as a moist solid or semi-solid slurry of white crystals. May explode under exposure to heat or fire. Used in pyrotechnics
strontium chlorate | Sr(ClO3)2 - PubChem.
Description: Strontium chlorate appears as a ...
Synonyms: STRONTIUM CHLORATE7791-10-...
Molecular Formula: Sr(ClO3)2 or Cl2O6Sr
How many grams are there in 2 x 1024 molecules of BCl3?
Answer:
How many grams are there in 1x10^24 molecules of BCl3? I use 117.17 as the molecular weight.
Looking for fresh, preservative-free food? Look no further!
How many grams are there in 1x10^24 molecules of BCl3? I use 117.17 as the molecular weight.
Did you try approaching this problem with dimensional analysis?
We know:
1×1024 molecules
117.17 g/mol
And we want our answer to be in g.
molecules ×gmolדconversion factor"=g
The conversion factor has to have units of
molmolecules in order for everything to work out.
What property do you know that has units of molmolecules?
I don’t know of any, but I do know that Avogadro’s number has units of moleculesmol. So for our conversion factor, we divide by Avogadro’s number, which is the same thing as multiplying by its inverse.
1×1024 molecules×117.17 gmol×mol6.022×1023molecules=
The “molecules” units cancel. The “mol” units cancel. Leaving us with “g”. The dimensions (units) work out. Now just do the math with the numbers.
Explanation:
How many different elements are involved in the reaction shown below?
2Fe + 6HC2H3O2 → 2Fe(C2H3O2)3 + 3H2
There are four. Fe, H, C, and O
Describe the different energy levels of electrons in an atom.
Answer:
Explanation:
If it is at a higher energy level, it is said to be excited, or any electrons that have higher energy than the ground state are excited. They are then called degenerate energy levels.
a compound is 43.7 phosphorus and 56.3 oxygen formula mass is 284 calculate emperical formula and molecular formula
Answer:
the molecular formula of a compound is P₄O₁₀.
M(P₂O₅) = 2 · Ar(P) + 5 · Ar(O) · g/mol.
M(P₂O₅) = 2 · 31 + 5 · 16 · g/mol.
M(P₂O₅) = 142 g/mol; molar mass of empirical formula.
M(PₓOₙ) = 284 g/mol; molecular mass of unknown compound.
M(PₓOₙ) : M(P₂O₅) = 284 g/mol : 142 g/mol.
M(PₓOₙ) : M(P₂O₅) = 2 : 1.
Explanation:
The empirical formula is [tex]P_{2}O_{5}[/tex] and The molecular formula is [tex]P_{4}O_{10}[/tex]
How to find the empirical and molecular formula? Convert each elements in grams to its amounts in moles.[tex](\frac{47.3g}{1})( \frac{1 mol}{30.97g})= 1.41 moles[/tex] of Phosphorus.
[tex](\frac{56.3}{1})(\frac{1 mol}{16}) = 3.51 moles[/tex] of Oxygen
Divide each resulting values by the smallest of these values.3.51/1.41 = 2.49 (rounded off 2.5)
1.41/1.41 = 1
Multiply these numbers with integers to get whole numbers.2.5 *2 = 5 (Oxygen)
2 *1 = 2 (Phosphorus)
Hence [tex]P_{2}O_{5}[/tex] is Empirical formula
and [tex]P_{4}O_{10}[/tex] is Molecular Formula
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Explain the process of photosynthesis in a well-written paragraph containing complete sentences. Use all of the following words:
xylem
phloem
carbon dioxide
stomata
sunlight
water
oxygen
sugar
Answer:
Photosynthesis is the process takes place in green plants in which the plants convert the carbon dioxide and water into the sugar molecule and oxygen in presence of the sunlight. The sunlight is trapped by the chlorophyll pigment, carbon dioxide uptake is facilitated by the stomata present on the leaves in the epidermis.
The water moves from the roots to the leaves and stem where it is used for photosynthesis and transpiration. The movement of water is through the xylem and sugar is move through the phloem from the leaves to a different part of the plant for nutrition and further process.
gallium chlorate decomposes
Answer:
Explanation:
in the decomposition of gallium chlorate, 75.0grams is heated to produce oxygen and gallium chloride.
yield for this reaction?
Reaction: N2(g) + 3 H2(g) → 2 NH3 (g)
Answer:
Yes, yield.
Explanation:
N2(g) + 3 H2(g) → 2 NH3 (g) balanced equation
First, find limiting reactant:
Moles H2 = 1.83 g x 1 mole/2 g = 0.915 moles H2
Moles N2 = 9.84 g N2 x 1 mole/28 g = 0.351 moles N2
The mole ratio of H2: N2 is 3:1, so H2 is limiting (0.915 is less than 3 x 0.351)
Theoretical yield of NH3 = 0.915 mol H2 x 2 mol NH3/3 mol H2 = 0.61 moles NH3
which reacts faster, rock salt or grains of salt? Why?
Answer:
salt
Explanation:
because it has a much larger volume ratio
!!!PLEASE HELP!!!!
What is the molarity of a solution with 0.5 moles of potassium fluoride dissolved to make 50 mL of solution?
A.0.1 mol/L
B.10 mol/L
C.1.72 mol/L
D.1450 mol/L
Answer: B
Explanation: molarity = concentration c= n/V = 0.5 mol/ 0.05 l = 10 mol/l
The molarity of a solution is the number of moles of its solute divided by volume in liters. The molarity of the 50 ml solution containing 0.5 moles of potassium fluoride is 10 M or 10 molar.
What is molarity ?Molarity is a common term used to express the concentration of a solution. It is the ratio of number of moles of solute particles to the volume of solution in liters. Hence, its unit is mol/L or molar.
The molarity of a solution is a colligative quantity as well as temperature dependent.
Given,
no.of moles of potassium fluoride salt in water = 0.5 moles.
volume of solution = 50 ml
1 L = 1000 ml
then 50 ml = 0.05 L.
Molarity = no.of moles of solute/ volume of solution in L
M = 0.5 moles/ 0.05 L
= 10 M.
Therefore, the molarity of the given solution is 10 molar.
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What is the acceleration due to gravity?
Answer:
The numerical value for the acceleration of gravity is most accurately known as 9.8 m/s/s. There are slight variations in this numerical value (to the second decimal place) that are dependent primarily upon on altitude.
Explanation:
sorry if i'm wrong
PLEASE HELP!! 10 POINTS!
what could the fourth quantum number of a 2s^2 electron be?
Answer:
D. ms=+1/2.
Explanation:
Hello there!
In this case, since the quantum numbers are known as:
* Principal quantum number (n) which cannot be zero. The allowed values of n are therefore 1, 2, 3, 4, and so on.
* Angular quantum number (l) is able to be any integer between 0 and n-1. If n = 2, for example, l can be either 0 or 1.
* Magnetic quantum number (m) is able to be any integer between -l and +l. If l = 3, m can be either -3, -2, -1, 0, +1, +2 or +3.
* Spin Quantum Number (ms): ms = +½ or -½. Accounts for the orientation of the spin axis of an electron as it is able to spin in only one of two directions.
Thus, since the fourth quantum number is ms, spin, we infer that the answer is D. ms=+1/2 because it represents the positive spin on 2s^2.
Best regards!
Answer: ms = +1/2
Explanation: a pex
Please help me out with this
Which plate is north of african plate and west of north american plate?
Please help me out
Given this balanced equation: CS2 + 3 O2 CO2 + 2 SO2
Calculate how many moles of SO2 can be produced with when given 4 moles of CS2.
58.67 g
Now calculate how many moles of SO2 can be produced with when given 4 moles of O2.
Which one is the limiting reactant (4 moles CS2 or 4 moles of O2)? How do you know?
Answer: The FitnessGram PACER Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The test is used to measure a student's aerobic capacity as part of the FitnessGram assessment. Students run back and forth as many times as they can, each lap signaled by a beep sound.
Explanation:
In an ideal gas, entropy is a measure of the
Answer:
Entropy is a measure of the degree of spreading and sharing of thermal energy within a system. For an ideal gas that expands at a constant temperature (meaning that it absorbs heat from the surroundings to compensate for the work it does during the expansion), the increase in entropy is given by ΔS= R1n (V2/V1)
Explanation:
hope this helps!
How many planets did early astronomers know about?
Answer:
5 Plants
Explanation:
Also can i have Brainlist
Match each scientist to their discovery regarding the atom
Thomson
Electrons have a charge of -1.
Rutherford
Atoms are indivisible
Millikan
Atoms have a positive nucleus
Dalton
Atoms contain electrons.
Answer:
Thomson--atoms cotain electron
Ernest Rutherford--atoms have a positive nucleus
R.A Millikan--electrons have Q=-1
Dalton--atoms are indivisible
Millikan---> Electrons have a charge of -1
Rutherford ---> Atoms have a positive nucleus
Thomson -----> Atoms contain electrons
Dalton --------> Atoms are indivisible
The atomic theory went through several modifications and different scientists proposed various models of the atom until our present conception of the atom was developed.
The atom was first defined as the smallest indivisible particle of a substance. This idea of "indivisibility" of the atom stems from Dalton's theory.
The fact that atoms were composed of negatively charged electrons was proven by the experiments of J.J Thompson using the cathode ray tube. Millikan's charge to mass experiment showed that the electron has a charge of -1.
Rutherford, in his famous gold foil experiment showed that atoms were composed of a positively charged nucleus.
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Which is the highest pressure?
a. 1.2 atm
b. 101 Pa
c. 101 kPa
d. 748 torr
