Chemistry Review

What is matter?

anything that takes up space and has mass

Mass is the ___ of matter an object has.

quantity

atoms

basic units of matter

What are atoms composed of?

protons, neutrons, and electrons

central area of the atom

nucleus

What are located in the nucleus of an atom?

protons and neutrons

What move around the nucleus of an atom?

electrons

The number of ___ is equal to the number of ___.

electrons; protons

How many electrons can the first orbital hold?

2

How many electrons can the second orbital hold?

8

How many electrons is the third orbital stable with?

8

valence electrons

the electrons on the outermost shell

elements

substances made up of the same type of atom

Which 4 elements make up around 96% of the mass of all kinds of living things?

CHON (carbon, hydrogen, oxygen, nitrogen)

Atomic Number = ___

\# of protons, # of electrons

Atomic Mass =

\# of protons + # of neutrons

\# of Neutrons =

atomic mass - atomic #

A

atomic number

B

chemical symbol

C

element name

D

atomic mass

Elements on the periodic table are organized in order of ___.

atomic number

periods of elements

rows that tell you the energy level

group/families of elements

columns that tell you the number of valence electrons

What do Lewis Dot diagrams represent?

valence electrons

isotopes

atoms of the same element that have a different number of neutrons

compounds

substances formed by bonding two or more elements in definite proportions

compound examples

water (H2O), carbon dioxide (CO2)

What does the chemical formula show?

the composition of the compound

octet rule

When the energy levels are not filled, atoms tend to react with other atoms to fill them.

chemical bonds

the force that holds together the atoms that make up compounds

Why do atoms form bonds?

to become more stable - they need a full outer shell of electrons

What are the two main types of strong chemical bonds?

ionic bonds and covalent bonds

ionic bonds

bonds in which electrons are transferred from one atom to another

ionic bond example

sodium chloride (table salt)

ions

charged atoms that have lost or gained electrons

Ions of opposite charge ___, forming ionic bonds.

attract strongly

covalent bonds

bonds in which electrons are shared between atoms

covalent bond example

methane

polar covalent bond

non-equal sharing of electrons

non-polar covalent bond

equal sharing of electrons

hydrophilic

water loving, ionic compounds, polar covalent

hydrophilic examples

salt, sugar, water

hydrophobic

water fearing, non-polar covalent

hydrophobic examples

oil, fats, waxes

molecules

two or more atoms bonded together

molecule examples

O2, H2