Pre-IB Chemistry Midterm

Hypothesis

testable statement; if-then structure

Mega

10^6

Kilo

10³

Hecto

10²

Deka

10^1

Deci

10^-1

Centi

10^-2

Milli

10^-3

Micro

10^-6

Nano

10^-9

mL

cm³

Liter

dm³

kL

m³

Length

meter

Mass

kilogram

time

second

Temperature

kelvin

Amount of substance

mole

Electric current

ampere

Luminous intensity

candela

Matter

anything that has mass and takes up space

Mass

measurement of the amount of matter w/o gravitational pull

Equation for Density

D=m/v

Equation for Volume

v=m/D

Equation for Mass

m=Dv

Atom

the smallest unit of an element that maintains the chemical identity of that element

Compound

a substance that can be broken down into simple stable substances

Physical change

A change in a substance that does not involve a change in the identity of the substance

Chemical change

A change in which one or more substances are converted into different substances

Reactants

substances that react in a chemical change(left side of the equation)

Products

Substances that are formed by the chemical change

Groups in a periodic table

vertical columns

Periods in a periodic table

horizontal rows

Properties of a metal

good electrical conductor, good heat conductor, malleability, ductile, tensile strength

Properties of Noble Gases

unreactive, stable, colorless, odorless, low melting and boiling points

When multiplying or dividing, you round to the number with the _____ of significant figures.

least number

When you add or subtract, it is to the ______.

least precise decimal place

If the number has no decimal point, start from ___ look for the first non-zero.

right to left

If the number has a decimal point, start from ___ and look for the first non-zero.

left to right

Accuracy

refers to the closeness of measurements to the correct or accepted value of the quantity measure

Precision

refers to the closeness of a set of measurements of the same quantity made in the same way

Theory

A broad generalization that explains a body of facts or phenomena

Diffusion

Spontaneous mixing of particles of two substances caused by their random motion

Effusion

a process by which gas particles pass through a tiny opening

Properties of Metalloids

less malleable than metals, semiconductors of electricity, solids at room temperature

Specific Heat Equation

c=q/mDT

Law of Conservation of Mass(Dalton’s Law)

Mass is neither created nor destroyed during ordinary chemical reactions or physical changes

Dalton’s Atomic Theory

All matter is composed of atoms, atoms are identical, cannot be subdivided, created or destroyed; in chemical reaction, atoms are combined, separated, or rearranged

Mass number

protons + neutrons

Average atomic mass

Based on the percent abundance of all naturally occurring isotopes

Atomic number

number of protons

Mass of an atom is located in the ____

nucleus

The volume of an atom is made up of ___

electrons

Isotopes

Atoms of the same element with different masses

Three forms of radiation

alpha, beta, gamma

Weakest form of radiation

alpha radiation

Strongest form of radiation

gamma waves

Nuclear Fusion

Low mass nuclei combine to form a heavier, more stable nucleus

Nuclear Fission

A very heavy nucleus splits into more-stable nuclei of intermediate mass

Ground State

the lowest energy state of an atom

Excited State

a state in which an atom has a higher potential energy than it has in its ground state

Electrons

negatively charged particles

Protons

positively charged particles

Neutrons

neutrally charged particles

Neutrons and protons are located ______

inside the nucleus

Electrons are located in ___

outside the nucleus

Control rods

neutron-absorbing rods that help control the reaction by limiting the number for free neutrons

Mass of Proton

1

Mass of Neutron

1

Mass of Electrons

0

Orbital

Three-dimensional region around the nucleus that indicates the probable location of an electron

Aufbau Principle

an electron occupies the lowest-energy orbital that can receive it

Pauli Exclusion Principle

no two electrons in the same atom can have the same set of four quantum numbers

Hund’s Rule

orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin state

Wavelength

the distance between corresponding points on adjacent waves

Electron Configuration

The arrangement of electrons in an atom

Shape of P Orbital

dumbell

Order of How to Fill up Orbitals

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s

Number of Orbitals in the Second Energy Level

4

Number of Electrons in S Orbital

2

Number of Electrons in P Orbital

6

Number of Electrons in D Orbital

10

Number of Electrons in F Orbitals

14

Number of Electrons in 4th energy level

32

Solids

definite shape and volume, incompressibility, definite melting point, high density

Liquids

definite volume, no definite shape, high density, incompressibility, diffusion, surface tension

Gases

no definite shape or volume, fluidity, low density, compressible

Electronegativity

the measure of ability of an atom in a chemical compound to attract electrons from another atom in the compound

Valence Electrons

The electrons available to be lost, gained, or shared in the formation of chemical compounds

The cathode ray experiment discovered ______

electrons

Rutherford discovered the _____

nucleus

Chemical bond

a mutual electrical attraction between the nuclei and valence electrons of different atoms that bind the atoms together.

Conservation of Energy

Energy is neither created nor destroyed

Nuclear Binding Energy

The energy released when a nucleus is formed from nucleons.

Positive side of Cathode Ray

Anode

Negative side of Cathode Ray

Cathode

Balancing a Nuclear Equation

1. The sum of the mass numbers of all reactants must equal the sum of the mass numbers of all products.

2. The sum of the atomic numbers of all reactants must equal the sum of the atomic numbers of all products.

_____ is shared in a chemical bond

Electrons

Hydrogen’s Location on the Periodic Table

It does not have the same properties as the group 1 elements

Units for Specific Heat

Calories or Joules per gram per Celsius degree