Periodic table

Question 1

Properties of metals

Answer 1

• Conduct heat and electricity
• Malleability
• Ductility
• Lustre
• Form cations

Question 2

Properties of non-metals

Answer 2

• Lack properties of metals
• Gases at normal temperatures
• More variation
• Form anions

Question 3

Atomic radii trends

Answer 3

Increase down a group; more electron shells + greater shielding
Decreases across a period; more protons

Question 4

Atomic radius definition

Answer 4

Half the distance between the nuclei of two atoms

Question 5

X-ray crystallography

Answer 5

Used to find the atomic radius of elements. Shoot xrays at an element, diffraction pattern reveals radius

Question 6

Ionic radii trends

Answer 6

Cations are smaller than parent atoms; more protons than electrons, lost outer shell, less shielding
Anions are larger than parent atoms; fewer protons than electrons, more repulsion

Question 7

Isoelectronic ions

Answer 7

Same number of electrons, different elements. In isoelectronic group, most negative = largest

Question 8

Metallic character trends

Answer 8

Increases down a group; easier to lose electrons b/c of greater radius
Decreases across period; harder to lose electrons b/c of smaller radius

Question 9

Ionization energy definition

Answer 9

Minimum energy needed to remove an electron from an atom.

Q -> Q+ + e-

Question 10

ionization energy trends

Answer 10

Decreases down a group; takes less energy b/c of greater radius
Increases across a period; takes more energy b/c of decrease in radius

Question 11

Electron affinity definition

Answer 11

Energy released/required when an electron is gained
A + e- -> A-
If energy is released, EA is negative and ion is stable
If energy is required, EA is positive and ion is unstable

Question 12

Electron affinity trends

Answer 12

Increases across a period; closer and closer to filling the outer shell
Decreases down a group; farther from nucleus

Question 13

Electronegativity trend

Answer 13

Decreases down a group; greater radius makes it harder to attract electrons. Increase in nuclear charge nullified by increase in shielding
Increase across a period; increase in nuclear charge + decrease in radius makes it more attractive

Question 14

Oxide behaviour

Answer 14

Metals are basic, some are amphoteric. Non-metals are acidic. Left to right, basic to acidic.

Question 15

Density of alkali metals

Answer 15

First 3 have densities lower than water. Increases down group

Question 16

Melting/boiling points of alkali metals

Answer 16

Lower than other metals. Decrease down group because metallic bonds get weaker as atomic radii increase

Question 17

Reactivity of alkali metals

Answer 17

Increases down a group - gets easier to lose electrons

Question 18

Reaction of alkali metals with water

Answer 18

Form alkali (metal hydroxide) and hydrogen gas

Question 19

Reaction of alkali metals with air

Answer 19

Burn in air to form metal oxides

Question 20

Reaction of alkali metals with chlorine

Answer 20

Burn in chlorine to form metal chlorides

Question 21

Colour of halogens

Answer 21

Darker down the group

Question 22

Melting/boiling points of halogens

Answer 22

Increase down a group as molecules get bigger and bonds get stronger

Question 23

States of halogens

Answer 23

Gas to solid down the group because of increased molar mass and stronger bonds

Question 24

Reaction of halogens with group 1 metals

Answer 24

Form metal halides, type of salt, ionic compound

Question 25

Reactivity of halogens

Answer 25

Decreases don the group - harder to attract electrons

Question 26

Reaction of halogens with hydrogen

Answer 26

Form hydrogen halides, gases, covalent

Question 27

Addition of halogen to solution with a less reactive halogen

Answer 27

Halogen will displace any element beneath it

Question 28

Properties of halogens

Answer 28

Non metals, don’t conduct electricity, brittle/crumbly, poisonous/smelly