periodicity

Question 1

Atomic number

Answer 1

The number of proton in the nucleus of atom.

Question 2

Mass number

Answer 2

The sum of the number of proton and neutron in the nucleus - also known as nucleon number.

Question 3

Periodicity

Answer 3

a repeating trend in properties of the elements across each period of the periodic table.

Question 4

Physical properties

Answer 4

the attraction between the negative electrons in their orbitals, and the positive protons in the nucleus

Question 5

Chemical properties

Answer 5

physical properties are properties that can be measured without changing the chemical composition of matter.

Question 6

Electronic configuration

Answer 6

a short-hand representation that shows how electrons occupy sub-shells in an atom.

Question 7

Sub-shell

Answer 7

a group of orbitals of the same type within a shell.

Question 8

Orbital

Answer 8

a region around the nucleus that can hold up to two electrons, with opposite spins.

Question 9

First ionisation energy

Answer 9

the energy required to remove one electron from each atom in one mole of gaseous atoms of an element to form one mole of gaseous 1+ ions.

Question 10

Second ionisation energy

Answer 10

the energy required to remove one electron from each ion in one mole of gaseous 1+ ions of an element to form one mole of gaseous 2+ ions.

Question 11

Atomic radius

Answer 11

the size of the atom, typically measured by the distance from the nucleus of the atom to the electron clouds around the nucleus.

Question 12

Nuclear attraction

Answer 12

the attraction between the negative electrons in their orbitals, and the positive protons in the nucleus.

Question 13

Shielding effect

Answer 13

the repulsion between electrons in different inner shells. shielding reduces the net attractive forces between the positive nucleus on the outer shell electrons.

Question 14

Metallic bonding

Answer 14

the electrostatic attraction between positive ions and delocalised ions

Question 15

Covalent bonding

Answer 15

the strong electrostatic attraction between shared pair of electrons and the nuclei of the bonded atom.

Question 16

Giant covalent lattice

Answer 16

a tree-dimensional structure of atoms, bonded together by strong covalent bonds.

Question 17

Giant ionic lattice

Answer 17

a three-dimensional structure of oppositely charged ions, bonded together by strong ionic bonds.

Question 18

Giant metallic lattice

Answer 18

a three-dimensional structure of positive ions and delocalised electron., bonded together by strong metallic bonds.

Question 19

Melting point

Answer 19

the temperature at which a given solid will melt.

Question 20

Boiling point

Answer 20

the temperature at which a liquid boils and turns to vapour.

Question 21

Solubility

Answer 21

the ability to be dissolved, especially in water.

Question 22

ionic bonding

Answer 22

ionic bonding is the electrostatic attraction between positive and negative ions.

Question 23

group

Answer 23

a vertical column in the periodic table. elements in a group have similar chemical properties and their atoms have the same number of outer shell electrons.

Question 24

period

Answer 24

a horizontal row of elements in the periodic table. Elements shows trend in properties across a period.

Question 25

simple molecular lattice

Answer 25

a three-dimensional structure of molecules, bonded together by weak intermolecular forces.

Question 26

shell

Answer 26

a group of atomic orbitals with same principal quantum number, n. also known as a main energy level.