atoms

Question 1

what is the structure of an atom. draw a diagram

Answer 1

nucleus in the centre with the protons (positive charge) and neutrons (neutral charge) in the nuleus. electrons (negative charge) circles around the shells

Question 2

symbol for potasium hydroxide

Answer 2

KOH

Question 3

Na + H20 = NaOH + H2.

BALANCE

Answer 3

2Na + 2H20 = 2NaOH + H2

Question 4

Na + Cl2 = NaCl. Which of these is the correct balanced equation?

Answer 4

You said: 2Na + Cl2 = 2NaCl

Question 5

Which of these is the correct balanced equation for the reaction between potassium and bromine?

Answer 5

You said: 2K(s) + Br2(g) = 2KBr(s)

Question 6

Which of these is the correct balanced equation for the reaction between potassium and water?

Answer 6

2K(s) + 2H20(l) = 2KOH(aq) + H2(g)

Question 7

compared to most other metals, what properties do the alkali metals have?

Answer 7

You said: low melting points and low densities

Question 8

When sodium hydroxide dissolves in water, what sort of solution is formed?

Answer 8

You said: alkaline

Question 9

Which gas is produced when lithium reacts with water?

Answer 9

hydrogen

Question 10

Which alkali metal is the most reactive out of lithium, sodium and potassium?

Answer 10

potassium

Question 11

Why is sodium stored under oil?

Answer 11

You said: to keep it away from air and water

Question 12

Which alkali metal is the softest out of lithium, sodium and potassium?

Answer 12

You said: potassium

Question 13

How many chlorine atoms are there in one chlorine molecule?

Answer 13

two

Question 14

Which of the properties below best describe the halogens?

Answer 14

You said: poor conductors of heat and electricity

Correct.

Question 15

Which is the most reactive halogen?

Answer 15

flourine

Question 16

Which of the statements below best describes the properties of the halogens as you go down group 7?

Answer 16

You said: The elements become less reactive and have higher melting points.

Question 17

fluorine is more reactive than chlorine. What will happen when chlorine is bubbled through a solution of sodium flouride

Answer 17

Chlorine will not displace fluorine when chlorine is bubbled through a solution of sodium fluoride.

Question 18

Why is neon used in neon lights?

Answer 18

You said: It gives off light when electricity passes through it.

Question 19

Why is helium is used in balloons?

Answer 19

You said: It is less dense than air.

Question 20

Which is the densest noble gas?

Answer 20

You said: radon

Correct.

Question 21

The noble gases are monatomic. What does this mean?

Answer 21

they exist as single atoms

Question 22

what is the group one metals aka

Answer 22

alkali metals

Question 23

predict the electronic structure of first 20 elements

Answer 23

H:1 He:2
2,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8
2,8,1 2,8,2 …………………………..

Question 24

describe the main properties of halegons

Answer 24

low melting points and boiling points
meltijg and boiling points increase as you go down the group
reactivity decreses as you go down the group
At 25*C, fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids.
The halogens become darker as you go down the group.

Question 25

why are group 0 elements or noble gases unreactive

Answer 25

they have a stable arrangement of electrons

Question 26

An element has the electronic structure 2,8,4. Which group is it in?

Answer 26

You said: Group 4

Question 27

Two elements have these electronic structures: 2,1 and 2,8,1. What can you say about the elements?

Answer 27

Elements with the electronic structures 2,1 and 2,8,1 are both in Group 1.

Question 28

What do the elements in a group have the same number of?

Answer 28

same number of electrons in their outer shell.

Question 29

What do the elements in a period have the same number of?

Answer 29

shells

Question 30

Which of these electronic structures belongs to a noble gas?

Answer 30

2

Question 31

When an element from group 1 reacts with water:

Answer 31

You said: A metal hydroxide and hydrogen are formed

Question 32

describe the properties of group one (alkali metals)

Answer 32

as you go down the group:
atomic number increases
atomic mass increases
energy needed to remove an electron decreases