Question 1

Determine the mass in grams of 1.15 × 10²³ atoms of cobalt. A) 0.191 grams B) 5.23 grams C) 11.2 grams D) 12.4 grams E) 308 grams

Accepted Answer

1.15 × 10^23 atoms of cobalt can be converted to moles by dividing with Avogadro's number (6.022 × 10^23). 
1.15 × 10^23 / 6.022 × 10^23 = 0.191 moles 
The molar mass of cobalt is 58.93 g/mol, so the mass of 0.191 moles is: 
0.191 moles x 58.93 g/mol = 11.2 grams 
Therefore, the answer is choice C, 11.2 grams.

Question 2

What is the correct number of atoms in one mole of neon? A) 10 B) 3.011 x 10²³ C) 6.022 × 10²³ D) 20 E) 12

Accepted Answer

One mole of any substance contains 6.022 × 10^23 particles (Avogadro's number). Since neon is an element, one mole of neon would contain 6.022 × 10^23 neon atoms.

Question 3

Determine the number of atoms in a copper strip that has a mass of 35.0 grams. A) 3.33 × 10²⁵ atoms B) 2.11 × 10²⁵ atoms C) 2.71 × 10²⁰ atoms D) 3.32 × 10²³ atoms E) 0.551 atoms

Accepted Answer

To determine the number of atoms in the copper strip, we need to use the concept of Avogadro's number and molar mass. The molar mass of copper is 63.55 g/mol, which means that one mole of copper has a mass of 63.55 g and contains 6.022 × 10²³ atoms. 
The number of moles of copper in the given strip can be calculated as:
moles of copper = mass of copper strip / molar mass of copper
moles of copper = 35.0 g / 63.55 g/mol ≈ 0.552 mol
Therefore, the number of copper atoms in the strip can be calculated as:
number of copper atoms = moles of copper × Avogadro's number
number of copper atoms = 0.552 mol × 6.022 × 10²³ atoms/mol ≈ 3.32 × 10²³ atoms
Therefore, the correct answer is D.

Question 4

Which of these elements is not a transition metal?
A) Cu
B) Fe
C) Na
D) Ag
E) Hg

Accepted Answer

Transition metals are the elements in the d-block of the periodic table, and Na (sodium) is not located in the d-block.

Question 5

Calculate the number of moles in a 25.0 g sample of carbon. A) 2.08 moles B) 13.0 moles C) 300 moles D) 1.51 × 10²⁵ moles E) 3.33 × 10^- ³ moles

Accepted Answer

The molar mass of carbon (C) is approximately 12.01 g/mol. To find the number of moles in a 25.0 g sample, use the formula: moles = mass (g) / molar mass (g/mol). Thus, moles = 25.0 g / 12.01 g/mol ≈ 2.08 moles.

Question 6

Which of the following is true?
A) Oxygen and sulfur are in the same group.
B) Oxygen and sulfur are in different groups.
C) Oxygen and sulfur are in the same period.
D) Oxygen and fluorine are in different periods.
E) Oxygen and nitrogen are in the same group .

Accepted Answer

Oxygen and sulfur are both in Group 16 of the periodic table, also known as the chalcogens.

Question 7

Calculate the number of moles in a 2.98 g sample of aluminum. A) 0.0124 moles B) 0.110 moles C) 80.4 moles D) 1.79 × 10²⁴ moles E) 1.62 × 10²⁵ moles

Accepted Answer

The molar mass of aluminum is 26.98 g/mol. Therefore, dividing the given mass by the molar mass gives the number of moles: 2.98 g / 26.98 g/mol = 0.110 moles.

Question 8

Calculate the number of moles of lead in a 442-gram lead anvil. A) 0.468 moles B) 2.13 moles C) 96.97 moles D) 6.022 × 10²³ moles E) 1.28 × 10²⁴ moles

Accepted Answer

To calculate the number of moles of lead, we need to divide the mass of the lead by its molar mass. The molar mass of lead is 207.2 g/mol. Therefore, the number of moles of lead in a 442-gram lead anvil is:

moles of lead = 442 g ÷ 207.2 g/mol = 2.13 moles

The answer is choice B, which is 2.13 moles.

Question 9

Bromine is a member of which group/family?
A) Halogens
B) Noble gases
C) Alkali metals
D) Transition metals
E) Alkaline earth metals

Accepted Answer

Bromine belongs to the halogen family/group which is found in Group 17 of the periodic table. Halogens include elements such as fluorine, chlorine, iodine, and astatine. They are highly reactive nonmetals and typically have seven valence electrons.

Question 10

Determine the mass in grams of one molecule of water, H₂O. A) 2.99 × 10^{− 23} g B) 1.08 × 10²⁵ g C) 10 grams D) 18 grams E) None of these.

Accepted Answer

The molecular mass of water (H2O) is approximately 18 g/mol. Using Avogadro's number (6.022 × 10^23 molecules/mol), the mass of one molecule of water can be calculated as (18 g/mol) / (6.022 × 10^23 molecules/mol) = 2.99 × 10^-23 g.

Question 11

One mole of nickel (Ni) has a mass of _____.
A) 28 amu
B) 28 g
C) 58.71 amu
D) 58.71 g
E) 30.71 g

Accepted Answer

The molar mass of nickel (Ni) is 58.71 g/mol, meaning that one mole of nickel has a mass of 58.71 g.

Question 12

Which of these groups is incorrectly matched with its group/family name? 
A) I
B) II
C) III
D) IV
E) V

Accepted Answer

Group II is incorrectly matched. The correct name for Group II is alkaline earth metals, not halogens.

Question 13

How many atoms does one mole of aluminum contain? A) 12 B) 26.98 C) 6.022 × 10²³ D) 12.044 x 10²³ E) 14

Accepted Answer

One mole of any substance contains Avogadro's number of particles, which is approximately 6.022 × 10^23. Therefore, one mole of aluminum contains 6.022 × 10^23 atoms.

Question 14

The atomic mass of fluorine (F) is 19.00. Which of the following is not true? A) An atom of F has a mass of 19.00 amu. B) One mole of F has a mass of 19.00 g. C) The mass of 6.02 x 1023 atoms of F is 19.00 g. D) The mass of 6.02 x 10 ²³ atoms of F is 19.00 amu. E) The approximate total number of protons and neutrons in fluorine is 19.

Accepted Answer

Option A is true because the atomic mass of fluorine is the mass of one atom of fluorine, which is 19.00 amu.
Option B is true because one mole of any element contains Avogadro's number of atoms or molecules, which in the case of fluorine would have a mass of 19.00 g.
Option C is true because 6.02 x 1023 atoms of fluorine, which is one mole of fluorine, would have a mass of 19.00 g.
Option E is true because the atomic mass of fluorine is the sum of the number of protons and neutrons in the nucleus of the fluorine atom, which is approximately 19.
However, option D is false because the mass of 6.02 x 1023 atoms of fluorine is 19.00 g, not 19.00 amu. The atomic mass unit (amu) is a unit of mass used for individual atoms, while grams are a unit of mass used for larger quantities of atoms or molecules.

Question 15

Strontium is a member of which group/family?
A) Halogens
B) Noble gases
C) Alkali metals
D) Transition metals
E) Alkaline earth metals

Accepted Answer

Strontium belongs to the group/family of alkaline earth metals, which includes elements with two valence electrons and relatively low electronegativity.

Question 16

Calculate the number of moles in a 233-gram sample of barium. A) 0.589 moles B) 1.70 moles C) 3.20 × 10⁴ D) 6.022 × 10²³ moles E) 1.02 × 10²⁴ moles

Accepted Answer

To calculate the number of moles, we need to divide the mass of the sample by the molar mass of the substance. The molar mass of barium is 137.33 g/mol.

Moles = Mass/Molar mass 
Moles = 233 g / 137.33 g/mol 
Moles = 1.695

Rounded to two significant figures, the answer is 1.70 moles, which is choice B.

Question 17

Determine the mass of one mole of silver. A) 107.87 amu B) 107.87 g C) 47 amu D) 47 g E) 6.022 × 10²³ amu

Accepted Answer

The atomic mass of silver is 107.87 g/mol, which means that one mole of silver has a mass of 107.87 grams.

Question 18

Determine the number of atoms in a piece of silicon that has a mass of 15.0 grams. A) 1.13 × 10²⁴ atoms B) 1.69 × 10²⁵ atoms C) 2.54 × 10²⁰ atoms D) 3.21 × 10²³ atoms E) 9.03 × 10²⁴ atoms

Accepted Answer

The answer of Determine the number of atoms in a...

Question 19

Which family/group is largely unreactive?
A) Halogens
B) Noble gases
C) Alkali metals
D) Transition metals
E) Alkaline earth metals

Accepted Answer

Noble gases are largely unreactive because they have a full outermost electron shell and therefore have little tendency to gain or lose electrons, making them stable.

Question 20

Determine the mass in grams of 3.45 × 10²⁵ molecules of oxygen, O_2. A) 0.556 grams B) 57.2 grams C) 458 grams D) 916 grams E) 1.83 × 10³ grams

Accepted Answer

The answer of Determine the mass in grams of 3.45...

Quiz 3: Atoms and Elements

Determine the mass in grams of 1.15 × 1023 atoms of cobalt.

What is the correct number of atoms in one mole of neon?

Determine the number of atoms in a copper strip that has a mass of 35.0 grams.

Which of these elements is not a transition metal?

Calculate the number of moles in a 25.0 g sample of carbon.

Which of the following is true?

Calculate the number of moles in a 2.98 g sample of aluminum.

Calculate the number of moles of lead in a 442-gram lead anvil.

Bromine is a member of which group/family?

Determine the mass in grams of one molecule of water, H2O.

One mole of nickel (Ni) has a mass of _____.

Which of these groups is incorrectly matched with its group/family name?

How many atoms does one mole of aluminum contain?

The atomic mass of fluorine (F) is 19.00. Which of the following is not true?

Strontium is a member of which group/family?

Calculate the number of moles in a 233-gram sample of barium.

Determine the mass of one mole of silver.

Determine the number of atoms in a piece of silicon that has a mass of 15.0 grams.

Which family/group is largely unreactive?

Determine the mass in grams of 3.45 × 1025 molecules of oxygen, O2.

Determine the mass in grams of 1.15 × 10²³ atoms of cobalt.

Determine the mass in grams of one molecule of water, H₂O.

Determine the mass in grams of 3.45 × 10²⁵ molecules of oxygen, O_2.