Final Exam Review – Chapter 3 (Atoms: The Building Blocks of Matter)

Question 1

An additional result of the gold foil experiment was that

Accepted Answer

the nucleus is very small and positively charged

Question 2

How many grams are in 2.50 mol of aluminum (Al)?

Accepted Answer

67.5 g

Question 3

Which of the following is a statement of Dalton's Atomic Theory?

Accepted Answer

all matter is composed of atoms

Question 4

Matter cannot be created or destroyed is the law of

Accepted Answer

conservation of mass

Question 5

Which of the following is a statement of Dalton's Atomic Theory (2 answers)?

Accepted Answer

atoms cannot be subdivided, created or destroyed, atoms combine in whole number ratios to form compounds

Question 6

The electron was discovered in which experiment?

Accepted Answer

the cathode ray experiment

Question 7

What is the molar mass (2 answers)?

Accepted Answer

the same number as the average atomic mass, the mass (g) of one mole of any substance

Question 8

What were some discoveries of the cathode ray experiments (2 answers)?

Accepted Answer

the particles were the same, regardless of cathode material, the particles were negatively charged

Question 9

Which of the following is a statement of Dalton's Atomic Theory (2 answers)?

Accepted Answer

all atoms of a given element are identical in size and mass, atoms are rearranged in chemical reactions

Question 10

What is the average atomic mass of an element?

Accepted Answer

a weighted average of all naturally occurring isotopes (amu)

Question 11

How many grams are in 3.55 x 1023 atoms of neon (Ne)?

Accepted Answer

11.9 g

Question 12

What does the atomic number represent?

Accepted Answer

number of protons

Question 13

A pure substance always has the same proportion of elements by mass is the law of

Accepted Answer

definite proportions

Question 14

CO and CO2 are compounds that follow the law of

Accepted Answer

multiple proportions

Question 15

The gold foil experiment (3 answers)

Accepted Answer

used alpha particles, disproved the plum pudding model, discovered the nucleus

Question 16

How many atoms are in 3.45 mol of carbon (C)?

Accepted Answer

2.08 x 1024 atoms

Question 17

What does the mass number represent?

Accepted Answer

number of protons and neutrons

Question 18

How many moles are in 5.00 g of magnesium (Mg)?

Accepted Answer

0.206 mol

Question 19

How many protons, neutrons, and electrons does the isotope 15N (nitrogen-15) have?

Accepted Answer

p = 7, n = 8, e = 7

Question 20

The oil drop experiment discovered the (2 answers)

Accepted Answer

charge of the electron, the mass of the electron

Questions 20