C2 The Periodic Table

Question 1

In 1869 Dmitri Mendeleev arranged the 50 elements known in what?

Answer 1

Table of elements

Question 2

How did Mendeleev order the elements in his table of elements?

Answer 2

By atomic number.

Question 3

Why were there gaps in Mendeleev’s table of elements?

Answer 3

The elements were put in order of mass and to keep elements with similar properties in the same vertical groups , he had to swap one or two elements round and leave a few gaps.

Question 4

Why were the gaps in Mendeleev’s table of elements clever?

Answer 4

Because they were left for undiscovered elements and allowed Mendeleev to predict their properties.

Question 5

How were Mendeleev’s predictions in comparison to the elements which were later discovered?

Answer 5

He made really good predictions about the chemical and physical properties of an element he called ‘ekasilicon’, we now know this as germanium.

Question 6

See page 19 for picture of periodic table.

Answer 6

.

Question 7

What does the periodic table represents?

Answer 7

Each element using its chemical symbol.

These can be used to write chemical formulas and equations.

Question 8

What does red represent on periodic table?

Answer 8

Reactive metals

Question 9

What does orange represent on periodic table?

Answer 9

Transition metals

Question 10

What does yellow represent on the periodic table?

Answer 10

Post-transition metals

Question 11

What does green represent on the periodic table?

Answer 11

Non metals

Question 12

What does blue represent on the periodic table?

Answer 12

Noble gases

Question 13

Why is there a dark line drawn on the periodic table?

Answer 13

It separates metals from non-metals

Question 14

Complete the sentence

The period to which the element belongs corresponds to the ………

Answer 14

…..number of shells

Question 15

What are the rows called on the periodic table?

Answer 15

Periods

Question 16

Complete the sentence

The group to which the element belongs corresponds to the……..

Answer 16

……number of electrons it has in its outer shell.

Question 17

How many elements do group 1 elements have in their outer shell?

Answer 17

1

Question 18

How many elements do group 0 have in their outer shell?

Answer 18

They have full outer shells of 8 electrons

except helium which has 2

Question 19

How many electrons do group7 elements have in their outer shell?

Answer 19

7

Question 20

What is the purpose of the columns on the periodic table?

Answer 20

Similar chemical properties form columns.

Elements with similar chemical properties react in similar ways

Question 21

How was the atomic number of each element found?

Answer 21

Once protons and electrons were discovered, the atomic number of each element could be found, based on the number of protons in its nucleus.

Question 22

How does the modern periodic table compare to Mendeleev’s table of elements?

Answer 22

The elements are in order of ascending atomic number and fit the same patterns that Mendeleev worked out.

Question 23

Using the periodic table, state how many elements barium has in its outer shell (1 mark)

Answer 23

2

Question 24

Based on its position in the periodic table, would you expect the chemical properties of potassium to be more similar to those of sodium or calcium? Explain your answer. (2 marks)

Answer 24

Potassium and sodium are both in group 1. Potassium and calcium are in differ groups. So the chemical properties of potassium should be closer to those of sodium than calcium (1 mark)

Because the elements in the same group have similar chemical properties (1 mark)