$$(0.70 \times 63) + (0.30 \times 65) = 63.6\ \text{amu}$$

Question 1

Which of the following statements best describes the trend in atomic radius as you move from left to right across a period in the periodic table?

Accepted Answer

Atomic radius decreases because the effective nuclear charge increases, pulling electrons closer.

Question 2

Which element is most likely to form a +2 ion based on its position in the periodic table?

Accepted Answer

Magnesium (Mg)

Question 3

A neutral atom of sulfur has an atomic number of 16 and a mass number of 32. How many neutrons does it contain?

Accepted Answer

$$18$$

Question 4

Which of the following electron configurations represents a noble gas in its ground state?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^6$$

Question 5

Which of the following best describes the difference between metals and nonmetals?

Accepted Answer

Metals tend to lose electrons to form cations, while nonmetals tend to gain electrons to form anions.

Question 6

Calculate the average atomic mass of an element with two isotopes: 70% with mass 63 amu and 30% with mass 65 amu.

Accepted Answer

$$(0.70 	imes 63) + (0.30 	imes 65) = 63.6\ 	ext{amu}$$

Question 7

Which of the following molecules has a trigonal planar shape according to VSEPR theory?

Accepted Answer

BF$$_3$$

Question 8

What is the maximum number of electrons that can occupy the d orbitals in a single energy level?

Accepted Answer

$$10$$

Question 9

Which of the following compounds is named correctly?

Accepted Answer

FeCl$$_2$$: Iron(II) chloride

Question 10

Which of the following bonds is considered ionic based on the difference in electronegativity?

Accepted Answer

A bond with an electronegativity difference of $$2.1$$

Question 11

Which of the following is the correct Lewis structure for methane (CH$$_4$$)?

Accepted Answer

A central C atom with four single bonds to four H atoms, no lone pairs on C.

Question 12

Which of the following is a decomposition reaction?

Accepted Answer

$$2H_2O \rightarrow 2H_2 + O_2$

Question 13

Balance the following equation: $$C_3H_8 + O_2$ \rightarrow CO_2$ + H_2O$$

Accepted Answer

$$C_3H_8 + 5O_2 \rightarrow 3CO_2 + 4H_2O$$

Question 14

Which of the following elements is a metalloid?

Accepted Answer

Silicon (Si)

Question 15

What is the abbreviated electron configuration for calcium (Ca, atomic number 20)?

Accepted Answer

$$[Ar] 4s^2$

Question 16

Which of the following best describes the charge of an oxygen ion in an ionic compound?

Accepted Answer

$$-2$$

Question 17

Which of the following is the correct name for P$$_2O$_5$$?

Accepted Answer

Diphosphorus pentoxide

Question 18

How many valence electrons does chlorine (Cl) have?

Accepted Answer

$$7$$

Question 19

Which of the following is a single replacement reaction?

Accepted Answer

$$Zn + 2HCl \rightarrow $$ZnCl_2$$ + H_2$

Question 20

Which of the following statements about ionization energy is correct?

Accepted Answer

Ionization energy increases across a period from left to right.

Exam #2 Study Guide: Atomic Structure, Periodic Table, Bonding, and Chemical Reactions

Study Guide - Practice Questions