C4.2

Question 1

1. What is the structure of an atom?

Answer 1

-a very small central positive nucleus made of protons and neutrons with electrons arranged in shells around the nucleus

Question 2

2. What are the relative masses of protons, neutrons and electrons?

Answer 2

• proton= 1
• neutron= 1
• electron= negligible

Question 3

2. What are the charges of protons, neutrons and electrons?

Answer 3

• proton= +1
• neutron= 0
• electron= -1

Question 4

3. What is the relationship between electrons and protons in an atom?

Answer 4

-in any atom the number of electrons equals the number of protons

Question 5

4. What is the same in all atoms of the same element?

Answer 5

-all the atoms of the same element have the same number of protons

Question 6

5. How are the elements in the Periodic Table arranged?

Answer 6

-in order of proton number

Question 7

6. What happens when some elements like lithium, sodium and potassium are heated?

Answer 7

-they emit distinctive flame colours

Question 8

6. What elements emit distinctive flame colours when heated?

Answer 8

-lithium, sodium, potassium

Question 9

6. What flame colours do lithium, sodium and potassium emit when heated?

Answer 9

• lithium= red flame
• sodium= orange/yellow flame
• potassium= lilac flame

Question 10

7. Why does light emitted from a particular element give a characteristic line spectrum?

Answer 10

-wavelengths of light can be recorded on a line spectrum

Question 11

7. What wavelengths do elements have?

Answer 11

-they have different wavelengths depending on their different electron arrangement

Question 12

8. What has the study of the spectra helped?

Answer 12

-the study of spectra has helped chemists to discover new elements

Question 13

8. What are examples of new elements discovered using the line spectrum?

Answer 13

• caesium and rubidium

- helium by the line spectra of the sun

Question 14

9. What is the discovery of some elements depended on?

Answer 14

• new practical techniques

- e.g. spectroscopy

Question 15

9. What is spectroscopy?

Answer 15

-the practical technique used to produce line spectrum

Question 16

10. How do you find the proton number from the Periodic Table?

Answer 16

-the bottom number

Question 17

10. How do you find the neutron number from the Periodic Table?

Answer 17

-ram (top number)= proton+ neutron

= relative atomic mass- proton number= neutron number

Question 18

10. How do you find the electron number from the Periodic Table?

Answer 18

-number of electrons= number of protons
-ram (top number)= proton+ neutron
= relative atomic mass- proton number= neutron number

Question 19

11. What is the electron arrangement in an atom?

Answer 19

2.8.8

Question 20

12. What happens to the shell of an atom across a period?

Answer 20

-a shell (or energy level) fills with electrons across a period

Question 21

12. What is an energy level of an atom?

Answer 21

-a shell of an atom

Question 22

13. What significant does the number of electron in an elements outer shell have?

Answer 22

-it relates to their group number

Question 23

14. What are the chemical properties of an element are determined by?

Answer 23

-its electron arrangement