Q6. Ann shines a ray of white light at a glass prism.
screen
prism
(a)
Tick one box in each row to show if each sentence is true or false.
true
false
The light refracts as it enters the prism.
The light refracts as it travels through the prism.
The light disperses as it leaves the prism.
The light forms a spectrum of colours on the screen.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

what is the question?

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8