Midterm review

Chem

g

Unit used for Mass

L

unit used for volume

Unit used for energy

J

Unit used for temperature

C or K

Unit used for length

M or ft

time

seconds mins hours

Density

the measure of how much mass is packed into a specific volume

Never

leading 0s?

Always

middle 0s?

sometimes, yes if there is a decimal, no if not

trailing zeros

If it is odd

it goes up

if its even

it stays

when you add or subtract you go based off of

the least to the Right of the decimal

when you multiply or divide you go based off

the least total numbers

what is matter?

anything in the universe that has mass (takes up space) and volume (occupies space)

light

which of the following has no matter?

Calcium

which of the following is an element

steel

which one of these is homogeneous? the rest are heterogeneous

solvent

the liquid substance

solutes

the solid substance

the reactant side

the left side

the product side?

the right side

A+2B→ AB2 is what type of reaction

Synthesis

AB2→A+2B is what type of reaction?

Decomposition

CH4+O2→CO2+HO is what type of reaction?

Combustion

AB+C→ CB+A is what type of reaction

Single replacement

AB+CD→AD+CB is what type of reaction?

Double replacement

what is an empirical formula?

A formula where any molecular formula is reduced (divide by greatest common factor)

how to find percent composition

divide the mass of one element in a compound by the total mass of the compound, then multiply by 100%

Ionic

Metal nonmetal

Covalent

Nonmetal nonmetal

remember to write a formula to find the charges on the periodic table and swap them to find their charges

ok

Protons charge mass and location

positive, 1.67 ×10^-27 kg, inside the nucleus

what is an amu

a tiny unit of mass used for atoms and molecules,

what are orbitals

3D regions around an atom's nucleus that describe the probability of finding an electron

Neutron charge mass and location

no charge, 1.67 × 10^-27 kg, inside the nucleus

Electron charge mass and location

Negative, 9.1 × 10^-31 kg, orbiting the nucleus

if atoms are neutral then the number of protons ____ the number of electrons because ____

the same as, the positive and negative charges balance perfectly

how can you tell how many protons an element has?

the atomic number

what are positive ions called and how are they formed

cations, and they form when a neutral atom loses one or more electrons,

what are negative ions called and how are they formed

anions, and they form when a neutral atom gains one or more extra electrons, resulting in more electrons (negative charge) than protons (positive charge)

isotopes

a version of a chemical element that has the same number of protons but a different number of neutrons

isotopes have in common

the same number of protons (same atomic number) and electrons

how are isotopes different

differ in their number of neutrons

how to draw a bohr diagram

ok