The Periodic Table

Question 1

How to determine valency electrons

Answer 1

Same as group number

Question 2

How to determine how many shells of electrons

Answer 2

Period- downwards 1 to 7

Question 3

Valency

Answer 3

Electrons needed to get full outer shell

Question 4

Metallic character

Answer 4

Metals lose electrons to form +ve ions, they react with O to form basic oxides, react with non metals to form ionic compounds

Question 5

Non-metallic character

Answer 5

Gain electrons to form -ve ions, share electrons to form covalent compunds

Question 6

Properties of alkali metals

Answer 6

Soft, low density, low mp and bp b/c weaker metallic bonds down group, very reactive (increases down group, atoms bigger down)

Question 7

Lithium with H2O observations

Answer 7

Fizzes and moves slowly, floats on surface

Question 8

Lithium and water reaction

Answer 8

2Li+ 2H2O->2LiOH+ H2

Question 9

Sodium obrervations with water

Answer 9

Fizzes faster, Becomes a ball, floats, moves faster

Question 10

Sodium equation with water

Answer 10

2Na+ 2H2O-> 2NaOH+ H2

Question 11

Potassium observations with water

Answer 11

Burns lilac flame, becomes a ball, fizzes vigorously, floats

Question 12

Potassium equation with water

Answer 12

2K+ 2H2O -> 2KOH + H2

Question 13

Why is a solution alkali

Answer 13

Produces OH

Question 14

What type of reaction are the alkali metals with the water

Answer 14

Exothermic

Question 15

Why are alkali metals reducing agents

Answer 15

Give electrons easily, cause substances to be reduced themselves being oxidised

Question 16

How are halogens

Answer 16

Diatomic

Question 17

Halogen isnt halide

Answer 17

Chlorine are two atoms joined and chloride is an isotope

Question 18

Fluorine formula and state

Answer 18

F2, gas and pale yellow

Question 19

Chlorine formula and state

Answer 19

Cl2, gas and pale green

Question 20

Bromine formula and state

Answer 20

Br2, liquid and red brown

Question 21

Iodine formula and state

Answer 21

I2, solid and black purple crystals

Question 22

Halogens reactivity pattern

Answer 22

Decreases down group as atoms get bigger so more distance less attractive force

Question 23

Mp and bp of halogens

Answer 23

Larger diatomic molecule means greater intermolecular force and harder to boil or melt (mo and bp decrease down group)

Question 24

General rule of halogen displacement

Answer 24

Any halogen in molecular form will displace halide ion from below it from a solution of one of its salts (chlorine displaces bromides and iodides, bromine displaces iodides)

Question 25

Characteristics of transition metals

Answer 25

Form coloured compounds, good catalysts, variable valency and often involved in redox reactions, variable oxidation states, tend to be hard and dense and high mp, relatively unreactive, used to make alloys

Question 26

Characteristics of noble gases (group 0)

Answer 26

Colourless and monatomic and gaseous, unreactive b/c full outer shell, density more down group as atoms become bigger

Question 27

Uses of noble gases

Answer 27

Baloons (helium), light signs (neon), headlamps (krypton), arc welding

Question 28

Chlorine with potassium bromide solution

Answer 28

Cl2+2KBr->2KCl+Br2 (all aq)
Ionic eqt:Cl2 + Br- ->2Cl- +Br2 (all aq)
Colour change: green to red brown

Question 29

Chlorine with potassium iodide solution

Answer 29

Cl2+2KI-> 2KCl + I2 (all aq)
Ionic eqt: Cl2 +2I- ->2Cl- + I2
Colour change: green to black/purple

Question 30

Bromine with potassium iodide solution

Answer 30

Br2 +2KI- ->2KBr- +I2
Ionic eqt: Br2+ 2I- ->2Br +I2
Colour change: From red to purple /black

Question 31

Notes of halogens

Answer 31

Iodine is there if with starch solution turns blue black, iodine used as antiseptic, halogens are soluble in organic solvents and bromine gives brown solution and iodine pink solution