$$\text{Number of electrons} = \text{Number of protons} - \text{charge}$$

Question 1

Which of the following best describes the properties of a metalloid?

Accepted Answer

Brittle solid, conducts electricity moderately well, can be shiny or dull

Question 2

According to the octet rule, why do sodium atoms form Na$$^+$$ ions?

Accepted Answer

To achieve the electron configuration of neon by losing one electron

Question 3

Which group on the periodic table contains the halogens?

Accepted Answer

Group 7A

Question 4

How many electrons are present in a P$$^{3-}$$ ion?

Accepted Answer

18

Question 5

Which of the following elements will form an ion with a charge of $$+3$$?

Accepted Answer

Al

Question 6

A potassium ion, K$$^+$$, has how many protons, neutrons, and electrons? (Atomic number = 19, mass number = 39)

Accepted Answer

19 protons, 20 neutrons, 18 electrons

Question 7

Which of the following atoms will form an ion with a charge of $$-1$$?

Accepted Answer

I

Question 8

What is the correct formula to calculate the number of electrons in an ion?

Accepted Answer

$$	ext{Number of electrons} = 	ext{Number of protons} - 	ext{charge}$$

Question 9

Which of the following is a property of nonmetals?

Accepted Answer

Powdery solids or gases

Question 10

A sample contains 12 protons, 12 neutrons, and 10 electrons. What is the identity and charge of this ion?

Accepted Answer

Mg$$^{2+}$$

Question 11

Which of the following transition metals can form more than one type of positive ion?

Accepted Answer

Fe

Question 12

What is the charge on the ion formed by sulfur?

Accepted Answer

$$-2$$

Question 13

Which of the following best explains why chlorine forms a Cl$$^-$$ ion?

Accepted Answer

It gains one electron to achieve the configuration of argon

Question 14

Which of the following ions has the same number of electrons as a neon atom?

Accepted Answer

Na$$^+$$

Question 15

A brittle solid that conducts electricity moderately well and is used in computer chips is most likely a:

Accepted Answer

Metalloid

Question 16

Which of the following ions is isoelectronic with Mg$$^{2+}$$?

Accepted Answer

Ne

Question 17

How many neutrons are present in $$^{32}S$^{2-}$$?

Accepted Answer

16

Question 18

Which of the following best describes why metals are good conductors of electricity?

Accepted Answer

They have loosely held valence electrons that can move freely

Question 19

Which of the following ions has 10 electrons?

Accepted Answer

O$$^{2-}$$

Question 20

A student claims that all elements in Group 2A will form ions with a $$+1$$ charge. Is this correct? Why or why not?

Accepted Answer

No, because they lose two electrons to form $$+2$$ ions

Atoms, Elements, and Ion Formation: Study Guide for General Chemistry

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