1-Periodic Table and Atomic Structure

Question 1

Atomic Orbital

Answer 1

region in space around a nucleus in which there is a high probability of finding an electron

Question 2

Relative Atomic Mass

Answer 2

average mass of atoms of element comared to 1/12 mass of carbon-12 isotope

Question 3

First Ionisation Energy n

Answer 3

minimum energy to remove most loosly-bound electrons from an isolated gaseous atom in its ground state

Question 4

Oxidation

Answer 4

loss of electrons or increase oin oxidation number

Question 5

Isostopes

Answer 5

atoms with same atomic number but different mass numbers

Question 6

(Atomic) Energy Number

Answer 6

fixed amount of energy of an electron in an atom

Question 7

Radioactivity

Answer 7

spontaneous breaking up of a nucleus to release alpha, beta or gamma radiation

Question 8

Atomic Radius

Answer 8

half the distance between the nuclei of two identical atoms joined by a single covalent bond

Question 9

Heisenberg’s Uncertainty Principle

Answer 9

it is not possible to measure the exact position and momentum of electron in atom simultaneously

Question 10

Alpha Particle

Answer 10

helium nucleus or particle consisting of 2 protons and 2 neutrons

Question 11

Principle of Mass Spectrometry

Answer 11

positively charged ions are seperated by mass when moving in a magnetic field

Question 12

Ground State

Answer 12

in lowest energy state or in n=1 level

Question 13

Excited State

Answer 13

higher energy atate or in n>1 level

Question 14

Atomic Number

Answer 14

number of protons in nucleus of an atom

Question 15

Radioisotope

Answer 15

radioactive isotope or isotope with unstable nucleus

Question 16

(Energy) Sub-Level

Answer 16

sub-division of a main energy level consisting of one or more oribtals of the same energy

Question 17

Mass Number

Answer 17

number of nucleons (protons and neutrons) in the atoms of an isotope

Question 18

Half Life

Answer 18

time taken for half of the nuclei in a sample of decay ot time taken for activity to reduce by half

Question 19

Oxidation Number

Answer 19

charge on atom if electrons distributed by rules

Question 20

Second Ionisation Energy

Answer 20

electron removed from monopositive ion

Question 21

Reduction

Answer 21

gain of electrons or decrease on oxidation number

Question 22

Cathode Rays

Answer 22

streams of negatively charged electrons which travel from the cathode to anode, are deflected by magnetic and electric fields, and have sufficient energy to moce a small objectm eg a paddle wheel

Question 23

(Bohr) Orbit

Answer 23

2-D pathway at fixed distance from nucleus where electron is definetely located

Question 24

Element

Answer 24

an element cannot be broken down into anything simpler

Question 25

Mendeleev's Periodic Law/ Sysytem

Answer 25

when elements are listed according to relative atomic mass, their chemical properties repeat periodically

Question 26

Modern Periodic Law/ System

Answer 26

when elements are listed according to atomic number, their chemical properties repeat periodically

Question 27

Aufbau Principle

Answer 27

electrons occupy the lowest available energy levels

Question 28

Dalton's Atomic Theory

Answer 28

all matter is made of indivisible small particles called atoms

Question 29

Empirical Formula

Answer 29

shows simplest whole number ratioof the different atoms in a molecule

Question 30

Molecular Formula

Answer 30

shows the number and type of each atom in a moleule of a compound

Question 31

Hund's Rule

Answer 31

when two or more orbitals of equal energy are available, electrons occupy them singly before filling them in pairs

Question 32

Law of Conservation of Matter/ Mass

Answer 32

during chemical reaction matter is neither created or destroyed

Question 33

Newland's Octaves

Answer 33

arrangement of elements in which the first and the eighth have similar properties

Question 34

Nuclear Reaction

Answer 34

process that alters the composition, structure, or energy of a nucleus

Question 35

Pauli Exclusion Princliple

Answer 35

no more than two electrons may occupy an orbital and they must have opposite spin

Question 36

(Radio)Carbon Dating

Answer 36

dates an object containing carbon based on C-14 to C-12 ratio

Question 37

Triad

Answer 37

group of 3 elements woth similar chemicla properties where the atomic weight of the middle one is approx. equal to the everage of the other two

Question 38

Oxidising Agent

Answer 38

substance that brings about oxidation in other substances (is reduced)

Question 39

Reducing Agent

Answer 39

substance that brings about reduction in other substances (is oxidised)

Question 40

Electrolysis

Answer 40

use of electricity to bring about chemical reaction in an electrolyte

Question 41

Electrolyte

Answer 41

compound which condicts electricity when molten or dissolvedd in water