Periodic Table + Group I

Question 1

in the periodic table, elements are arranged in order of _________ _______ _____

Answer 1

increasing proton number

Question 2

horizontal rows are called?

Answer 2

periods, moving across a period, each successive atom of the elements gains one proton and one electrons

Question 3

vertical columns are called?

Answer 3

groups, which are referred to as ‚families‘ because they have similar characteristics (eg group 1)

this is because they have the same number of electrons in their outer shell/ same valencies

Question 4

why do metals become more reactive as they go down the periodic table?

Answer 4

as the metal atoms get bigger, the outer electrons get further away from the nucleus and can be removed more easily to form positive ions. so the larger metal can react more easily and form compounds

Question 5

why do non-metals get more reactive as they go down the periodic table?

Answer 5

the smaller the atom, the easier it is to accept electrons and form ions

• elements are bigger (more shells of electrons)
• outershell electron is further from the nucleus and feels the strong attractive force of the nucleus less
• the outer electron is more easily lost

Question 6

when did mendelev publish his work on the periodic table?

Answer 6

1871

Question 7

why are group 1 metals called alkali metals?

Answer 7

they react with water to produce an alkaline solution

Question 8

properties of group 1 metals

Answer 8

• soft to cut
• shiny when cut, but tarnish quickly
• very low melting points, decrease down the group
• very low densities compared with most metals: they float on water
• very reactive, stored in oil to prevent reaction with air and water. reactivity increases down the group

Question 9

reactions with air or oxygen: observations

Answer 9

burn easily and their compounds have coloured flames:

lithium: red
sodium: orange/yellow
potassium: lilac

Question 10

reactions with water: observations

Answer 10

• float on surface, moving around rapidly
• both sodium and potassium, the heat of the reaction melts the metal so it forms a sphere: bubbles of gas are given off and the metal „dissapears“
• hydrogen gas produced burns with a squeaky pop
• the resulting solution is alkalis

Question 11

reactions with chlorine: observations

Answer 11

the metals react vigourously, burning in chlorine to form a white solid, the metal chloride

Question 12

equations for reaction with oxygen/ air

Answer 12

lithium + oxygen —> lithium oxide

4Li + O,2 —> 2Li,2O

Question 13

reactions with water: equations

Answer 13

lithium + water —> lithium hydroxide + hydrogen

2Li + 2H,2O —> 2LiOH + H,2

Question 14

equations for reaction with chlorine

Answer 14

lithium + chlorine —> lithium chloride

2Li + Cl,2 —> 2LiCl

Question 15

compounds of group 1 metals

Answer 15

• most are solid/ white/ colourless
• soluble in water
• sodium chloride: table salt
• potassium nitrate: a fertilizer
• lithium hydroxide: removes carbon dioxide in air-conditioning systems

Question 16

what are group 1 metals also called?

Answer 16

alkali metals

Question 17

observations

Answer 17

• float, move, fizz (release hydrogen)
  turn UI blue

K- lilac flame
Na- orange flame