Chemical Interactions

Chapter 2 ReviewGood Luck!

How do the properties of a compound compare with the

properties of the elements that make it?

They are often quite different

What two factors determine the properties of a compound?

the types of atoms it contains and how the atoms are arranged

How do we represent compounds?

by a chemical formula

NaNO3 has how many oxygen atoms?

Three

What is a subscript?

a subscript is a number written to the right of a chemical symbol and slightly below it.

Write the formula for one atom of nitrogen and one atom of oxygen.

NO

How can millions of compounds be made from the atoms of about 100 elements

atoms can combine in many different ratios

What do you get when an atom loses or gains an electron?

an ion

What do you call the force of attraction between positive

and negative ions?an ionic bond

What type of bond holds a crystal together?

Ionic bond

What is the name of MgO

magnesium oxide

What type of bond is formed when electrons are shared?

covalent

What type of bond forms from unequal sharing of electrons?

Polar covalent

What is responsible for many of the properties of substances?

their structure

What type of bond is found in individual molecules?covalent

What part of an atom is involved in chemical bonding?

electron cloud

What property of the electrons in a metal gives the metal its

properties?

They move easily

Are covalent compounds good conductors of electricity when dissolved? Why or Why not?No, molecules stay together and do not conduct an electrical current.

How do metal atoms bond together?

Metal atoms share electrons with many other metal atoms at the same time.

Why do ionic compounds have high melting points?

Each ion in a crystal is rigidly bonded to the several ions that surround it. Because each ion is strongly bonded to other ions, much energy has to be added to break the bonds.

What are three forms of the element carbon?

Graphite, diamond, and fullerene

Most substances arecompounds

All compounds are made of

atoms of two or more elements

The chemical formula for a compound have one barium (Ba) ion and two chloride (Cl) ions is

BaCl2

The 4 in the chemical formula CH4 means there are

four hydrogen atoms to one carbon atom

An atom becomes a positive ion when it

loses an electron to another atom

A polar covalent bond forms when two atoms

share two electrons unequally

Metallic bonds make many metals

good conductors of electricity