Revision topic 3

Question 1

By who was the periodic table developed?

Answer 1

Dmitri Mendeleev

Question 2

How did Mendeleev arrange the elements in the periodic table

Answer 2

by putting them in order from their atomic masses

Question 3

Why didn’t people believe Mendeleev

Answer 3

because he left gaps in his periodic table, he had some elements here that don’t belong like the noble gas argon with the alkali metals, he also wasn’t a proven scientist making people doubtful of him

Question 4

what are the metals in the first group called?

Answer 4

alkali metals

Question 5

what are the properties of group 1 alkali metals

Answer 5

1. they are very reactive to the point where they are stored under oil to stop them from reacting with oxygen
2. very soft that they can be cut by a knife easily
3. the have very low density where they can float on water
4. they have low melting and boiling points
5. they don’t conduct electricity
6. they have shiny silvery surfaces.

Question 6

explain the chemical properties of alkali metals

Answer 6

they have 1 electron on their outer shell meaning that they need to lose 1 electron to gain a stable (noble gas) structure making them very reactive

Question 7

what happens when group 1 alkali metals react with water

Answer 7

the basic features are that they would float on the water, they would produce fiz that shows that hydrogen is being formed, and if the metal is very reactive it can cause an explosion or catch fire

what is formed is metal hydroxide and hydrogen

Question 8

what other reactions does group 1 alkali metals have

Answer 8

reacting vigorously with non-metals such as chlorine gas, to produce metal chlorides that are white solids that become colorless when dissolved in water

Question 9

what are transition metals properties

Answer 9

1. good conductors of heat and electricity
2. they are hard and strong
3. they have high melting and boiling points
4. they are shiny and silvery
5. they have high densities
6. very unreactive

Question 10

the transitional metals have different colored compounds depending on…

Answer 10

the number of ions with would have

Question 11

what are halogens?

Answer 11

they are group 7 elements, they are poisonous non-metal that have different colored vapors.

Question 12

how does displacement reactions work with halogens

Answer 12

less reactive halogens get displaced by higher reactive halogens in chemical equations

Question 13

explain why group 1 elements get more reactive as you go down the periodic table

Answer 13

as you go down group 1 the reactivity increases because the electronic shielding increases making the electrostatic force between the negative outer shell electrons and the positive protons in the nucleus get weaker making it easier to lose electrons

Question 14

explain why group 7 elements get more reactive as you go up the periodic table

Answer 14

as you go up group 7 the reactivity increases because the electronic shielding decreases making the electrostatic force between the negative outer shell electrons and the positive protons in the nucleus get stronger making it easier to gain electrons