$\text{Atomic mass} = \sum_{n} (\text{fraction of isotope } n) \times (\text{mass of isotope } n)$

Question 1

Which scientist is credited with discovering the electron using cathode ray experiments?

Accepted Answer

J.J. Thomson

Question 2

What is the correct formula to calculate the atomic mass of an element with multiple isotopes?

Accepted Answer

$	ext{Atomic mass} = \sum_{n} (	ext{fraction of isotope } n) 	imes (	ext{mass of isotope } n)$

Question 3

A neutral atom of chlorine has an atomic number of 17. How many electrons does it have?

Accepted Answer

17

Question 4

Which of the following statements about metals is FALSE?

Accepted Answer

They tend to gain electrons when they undergo chemical changes.

Question 5

What is the charge of the silver cation in AgCl?

Accepted Answer

+1

Question 6

Which element will have properties most similar to tin (Sn)?

Accepted Answer

Lead (Pb)

Question 7

How many neutrons are in the isotope $^{22}_{10}	ext{Ne}$?

Accepted Answer

12

Question 8

Which law states that matter cannot be created or destroyed in a chemical reaction?

Accepted Answer

Law of conservation of mass

Question 9

A sample contains 8 g of oxygen atoms. How many moles of oxygen atoms are present?

Accepted Answer

$0.5$ mol

Question 10

Which of the following is a property of nonmetals?

Accepted Answer

They tend to gain electrons during chemical changes.

Question 11

What is the molar mass of $	ext{Ca(OH)}_2$?

Accepted Answer

$74$ g/mol

Question 12

Which of the following elements is a metalloid?

Accepted Answer

Silicon (Si)

Question 13

What is Avogadro's number?

Accepted Answer

$6.02214 	imes 10^{23}$

Question 14

An atom of aluminum forms a $	ext{Al}^{3+}$ ion. How many electrons does it have?

Accepted Answer

10

Question 15

Which group in the periodic table tends to form $-1$ ions?

Accepted Answer

Group 7A (Halogens)

Question 16

A sample contains $4$ g of oxygen atoms. How many oxygen atoms are present?

Accepted Answer

$1.51 	imes 10^{23}$

Question 17

Which of the following is NOT a property of metalloids?

Accepted Answer

They are good conductors of heat and electricity.

Question 18

What is the mass of sodium containing $3$ mol of Na atoms?

Accepted Answer

$69$ g

Question 19

Which law led to the development of Dalton's atomic theory by showing that elements combine in simple whole-number ratios?

Accepted Answer

Law of multiple proportions

Question 20

How many moles of Na atoms are in $46$ g of Na?

Accepted Answer

$2$ mol

Chapter 2 Atoms and Elements: Structure, Isotopes, Periodic Table, and the Mole

Study Guide - Practice Questions