ATOMIC THEORY DEFINITIONS

Question 1

Alpha Particle

Answer 1

a helium nucleus with positive radition made up of 2 protons and 2 neutrons

Question 2

Atomic Number

Answer 2

number of protons in the neucleus of an atom

Question 3

Atomic orbital

Answer 3

the space around the neucleus of an atom where there is a high probability of finding an electron

Question 4

Atomic Radius

Answer 4

half the distamce between the nuclei of 2 atoms of the same element joined together by a covalent bond

Question 5

Aufbau Principle

Answer 5

Electrons will always occupy the lowest available energy level

Question 6

Bond energy

Answer 6

the average amount of energy needed to break a band and seperate atoms of the same chemical species in the gaesous state

Question 7

Cathode Rays

Answer 7

beams of negative particles called electrons

Question 8

Compound

Answer 8

substance made up of 2 or more different types of atoms held together by a chemical bond

Question 9

Daltons Atomic Theory

Answer 9

Atoms are made up of small indivisible particles and atoms of the same element are identical.

Question 10

Electronegativity

Answer 10

the relative measure of attraction that the neuleus of an atom has for the shared electrons in a covalent bond.

Question 11

Electronic configuration

Answer 11

the description of the number and arrangement of electrons in the energy level and sublevels of an atom.

Question 12

Element

Answer 12

an element is a substance that cannot be broken down into simplier substances by chemical means.

Question 13

Energy Level

Answer 13

the fixed amount of energy that an electron in an atom can have

Question 14

Energy Sublevels

Answer 14

A group of atomic orbitals with the same energy value

Question 15

First Ionisation Energy

Answer 15

The minimum amount of energy needed to remove the most loosely bound electron from a gaseous atom in ground state

Question 16

Ground State

Answer 16

The minimum and most stable amount of fixed energy an electron in an atom can have, the lowest energy level.

Question 17

Half Life

Answer 17

the time taken for half the nuclei of a radioactive sample to decay

Question 18

Heinsberg’s Uncertainty Principle

Answer 18

states that it is impossible to know the location and speed of an electron at the same time

Question 19

Hund’s Rule

Answer 19

The P and D sublevels fill up singularly before doubling up

Question 20

INTRAmolecular forces

Answer 20

forces of attraction within a molecule

Question 21

INTERmolecular forces

Answer 21

forces of attraction between different molecules

Question 22

Isotopes

Answer 22

atoms with the same number of protons but different number of neutrons giving different mass numbers

Question 23

Mass Number

Answer 23

number of protons and neutrons in the nucelus of the atom

Question 24

MOlecule

Answer 24

a substance made up of two or more atoms held together by chemical bonds

Question 25

Paulis Excluction Principle

Answer 25

no more than 2 electrons can occupy an energy sublevel and they must have opposite spins

Question 26

Periodic System/ Periodic Law

Answer 26

the elements in the periodic table are listed in order of increasing atomic mass and the properties are repeated at regular intervals

Question 27

Pi Bonds

Answer 27

covalent bond formed by the sideways overlaping of atomic orbitals