Atomic Structure

Question 1

1. What is an element?

Answer 1

1. A substance made of one type of atom.

Question 2

2. What is a compound?

Answer 2

2. A substance made of two or more elements chemically combined.

Question 3

3. What is a mixture?

Answer 3

3. A substance made of two or more elements or compounds NOT chemically combined.

Question 4

4. What technique do you use to separate water from salt water?

Answer 4

4. Distillation. The water will evaporate and then condense. The salt will remain.

Question 5

5. What technique do you use to separate sand from salt water?

Answer 5

5. Filtration. The sand will be left in the filter (residue).

Question 6

6. How many atoms are in a molecule of CO2

Answer 6

6. 3

Question 7

7. How many elements are in a molecule of CO2

Answer 7

7. 2 (carbon and oxygen)

Question 8

8. Write the word equation for the reaction between iron and oxygen to make iron oxide.

Answer 8

8. Iron + oxygen –> iron oxide

Question 9

10. Describe the plum pudding model of the atom.

Answer 9

10. A cloud of positive charge with small negatively charged electrons scattered in it.

Question 10

11. What two conclusions were made from the alpha particle scattering experiments.

Answer 10

11. The mass of an atom is concentrated in the centre (nucleus). The nucleus is charged.

Question 11

12. How did Bohr and Chadwick improve the atomic model?

Answer 11

12. Electron shells

Question 12

13. What is the radius of the atom?

Answer 12

13. 0.1nm

Question 13

14. How big is radius of the nucleus compared to the radius of the atom?

Answer 13

14. 1/10,000 time smaller

Question 14

15. What is 1nm in metres in standard form?

Answer 14

15. 1 x 10-9 m

Question 15

16. What is the relative mass of protons, neutrons and electrons?

Answer 15

16. 1,1,0

Question 16

17. What is the relative charge of protons, neutrons and electrons?

Answer 16

17. +1, 0 , -1

Question 17

18. What does the atomic number tell you about an atom?

Answer 17

18. The number of protons (which is equal to the number of electrons)

Question 18

19. What does the mass number tell you about an atom?

Answer 18

19. The total number of protons and neutrons.

Question 19

20. How many protons, neutrons and electrons are in sodium?

Answer 19

20. 11, 12, 11

Question 20

21. How do atoms become ions?

Answer 20

21. Lose or gain electrons

Question 21

22. What is an isotope?

Answer 21

22. Same element, different number of neutrons

Question 22

23. How many electrons fit into the first, second and third electron shells?

Answer 22

23. 2,8,8

Question 23

24. Why do elements in the same column of periodic table have similar chemical properties?

Answer 23

24. Same number of electrons in outer shell.