Unit 3 Study Guide

Question 1

Is water a polar or a nonpolar molecule? Why?

Answer 1

Water is polar because of its uneven charges

Question 2

What happens when a polar molecule combines with a nonpolar molecule?

Answer 2

The combination will NOT form a solution

Question 3

What is electronegativity and what is it used for?

Answer 3

Electronegativity is the ability of an ion to attract electrons. It is used to predict the types of bonds that a molecule consists of.

Question 4

Explain how a nonpolar molecule can have polar bonds.

Answer 4

Polar bonds on opposite sides of a molecule can nullify each other if they are equal, thus making a non polar molecule. Ex: O=C=O

Question 5

How do you know the number of valence electrons an atom has?

Answer 5

The group number

Question 6

Where do the radioactive elements begin on the periodic table and what does it mean to be radioactive?

Answer 6

Every atom with an atomic number of 84 (Polonium) or higher is radioactive. Radioactive molecules are highly unstable and undergo radioactive decay.

Question 7

What are valence electrons?

Answer 7

Electrons on the outermost shell of an atom

Question 8

What subatomic particles determine chemical properties?

Answer 8

Electrons

Question 9

When are Roman numerals used in chemical formulas?

Answer 9

To identify the number of valence electrons that a transition metal has

Question 10

What does the octet rule have to do with noble gases?

Answer 10

Noble gases have a full octet, or 8 electrons on their outer shell.

Question 11

What does the charge of an ion represent?

Answer 11

The charge of an ion represents the relative number of protons to electrons

Question 12

What does the octet rule state and how does it apply to ionic versus covalently bonded compounds?

Answer 12

The octet rule states that atoms gain and lose electrons to become stable, which means to have a full valence shell.

Question 13

What is a salt?

Answer 13

A salt is the product of a reaction between an acid and a base

Question 14

What types of ions end in -ide?

Answer 14

Anions

Question 15

What are the elemental characteristics of ionic compounds compared to covalent compounds?

Answer 15

Ionic compounds contain both a metal and a nonmetal while covalent compounds only contain nometals

Question 16

What is the definition of an ionic bond?

Answer 16

The electrostatic forces that hold ions together in ionic compounds

Question 17

How can you differentiate between a polar covalent molecule and a nonpolar covalent molecule?

Answer 17

Nonpolar bonds have an equal share of electrons while polar bonds do not.

Question 18

How does hydrogen bonding affect the physical characteristics of a compound?

Answer 18

The compound turns into an acid

Question 19

How do you know the charge of a transition metal from its formula?

Answer 19

The Roman numeral to the right of the transition metal

Question 20

What is the definition of an isotope?

Answer 20

An atom with a different number of protons and neutrons

Question 21

What types of molecules have Greek prefixes in their names?

Answer 21

Covalent

Question 22

List all the differences between ionic and covalent compounds including their chemical properties (melting points, conductivity, solubility).

Answer 22

Ionic- high melting, conduct in water, soluble with other ionic compunds
Covalent- low melting, not very conductive, soluble with other covalent compounds

Question 23

Where are cations versus anions on the periodic table?

Answer 23

Cations- left of carbon group

Anions- right of carbon group

Question 24

What does it mean when an anion ends in -ate or -ite?

Answer 24

Atoms that end in -ate generally have one more oxygen atom than those that end in -ite

Question 25

How can an acid be identified by its formula?

Answer 25

Acids have solely hydrogen and no oxygen (ex: HCl) while bases contain hydroxide (ex: NaOH)

Question 26

When is the prefix hydro- used as opposed to the ending -ic or -ous in naming acids?

Answer 26

Hydro- indicates that a compound has a hydrogen atom and is part of a binary (two word) compound. -ic and -ous are used in oxyacids, which consist of a hydrogen atom, nonmetal, and a varying number of oxygen atoms.