The periodic table

Question 1

Before 1800 how were the elements classified?

Answer 1

By atomic mass

Question 2

Give two reasons Newlands Octaves were criticised

Answer 2

He mixed up metals & non metals, He did not leave any gaps, his groups contained elements that did not have similar properties

Question 3

Why did Mendeleev leave gaps?

Answer 3

For elements that had not yet been discovered

Question 4

Describe the relationship between group number and period number and number of electrons

Answer 4

Group number determines the number of electrons in the outer shell and period number identifies the number of shells an element has

Question 5

As you go down the group of alkali’s, describe any patterns in reactivity and density

Answer 5

Reactivity and density in crease

Question 6

Explain why the reactivity increases

Answer 6

outer electron more easily lost because it is further from the positive charged nucleus

Question 7

Write a balanced symbol equation between reaction with Lithium and water

Answer 7

2Li(s) + 2H2O(l) –> 2LiOH(aq) + H2(g)

Question 8

Explain why group 7 elements get less reactive as you go down the group

Answer 8

It is harder to gain an extra electron because the space is further away from the nucleus

Question 9

Write a balanced equation for the displacement of Bromine from potassium Bromide

Answer 9

Cl2(g) + 2KBr (aq) –> Br2(aq) + 2KCl(aq)

Question 10

Transition metals are used as catalysts discuss three examples of reaction that use TM as catalysts in industry

Answer 10

Iron in the Haber Process, Manganese Oxide in the decomposition of Hydrogen Peroxide, Nickel in the manufacturing of margarine