2. MATTER Learning Outcome At the end of this topic, students should be able : (a) (a) Identify and describe proton, electron as subatomic particle. and neutron as subatomic particle. (b) proton number, Z, nucleon (b) Define proton number, Z, nucleon number, A and isotope. number, A and isotope. Write isotope notation.

3. 1.1ATOMS AND MOLECULES Define proton number, nucleon number and isotopes & write isotopes denotation MATTER CONTENTS Identify and describe protons, electrons and neutrons as sub-atomic particles Navigation button

4. 1.1ATOMS AND MOLECULES Define proton number, nucleon number and isotopes & write isotopes denotation MATTER CONTENTS Identify and describe protons, electrons and neutrons as sub-atomic particles Navigation button Definition of protons, electrons and neutron Identify and describe protons, electrons and neutrons as sub-atomic particles

5. 1.1ATOMS AND MOLECULES Define proton number, nucleon number and isotopes & write isotopes denotation MATTER CONTENTS Identify and describe protons, electrons and neutrons as sub-atomic particles Navigation button Definition of proton number (Z), nucleon number (A) & isotopes Define proton number, nucleon number and isotopes & write isotopes denotation

6. INTRODUCTION Matter Anything that occupies space and has mass. e.gair, water, animals, trees, atoms, ….. All matter consist of tiny particles called atoms

7. Objective: At the end of the lesson, you should be able to: 1) Identify and describe protons, electrons and neutrons as sub-atomic particles TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules This page will revises the simple ideas about atomic structure that you have come across in an introductory chemistry course (i.e. SPM). You need to be confident about this before you go on to the more difficult ideas about atom. THE SUB-ATOMIC PARTICLES An atom is the smallest unit of a chemical element/compound. In an atom, there are three subatomic particles: -Proton (p) -Neutron (n) Electron (e) Back to content Packed in a small nucleus Move rapidly around the nucleus of an atom

8. Modern Model of the Atom Electrons move around the region of the atom. - - electron nucleus Proton ( positive charge) + + Neutron (neutral)

9. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules X A Z Atomic symbol Nucleon number or mass number Proton number or atomic number Proton no.Nucleon no.Isotopes Pre-testExampleExercise Past year Question Back to content

10. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules Proton no.Nucleon no.Isotopes X A Z Atomic symbol Nucleon number or mass number Proton number or atomic number Pre-testExampleExercise Past year Question Proton number (Z) is the number of protons in the nucleus of each atom of an element. Also known as atomic number In a neutral atom, the number of protons is equal to the number of electrons. Proton no.

11. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules Proton no.Nucleon no.Isotopes X A Z Atomic symbol Nucleon number or mass number Proton number or atomic number Pre-testExampleExercise Past year Question Nucleon number (A) is the total number of neutrons and protons present in the nucleus of an atom of an element. Also known as mass number Nucleon no.

12. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules Proton no.Nucleon no.Isotopes X A Z Atomic symbol Nucleon number or mass number Proton number or atomic number Pre-testExampleExercise Past year Question Isotopes, atoms that have the same proton number but different nucleon number. i.e. Hydrogen has three isotopes H H H 1111 2121 3131 Isotopes

13. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules X A Z Atomic symbol Nucleon number or mass number Proton number or atomic number Proton no.Nucleon no.Isotopes Pre-testExampleExercise Past year Question Nucleon number = proton no. + no. of neutrons. So, the number of neutrons is equal to the different between the nucleon no. & the proton no. or ( A-Z). Ex. Nucleon no. of fluorine is 19 & proton no. is 9. Thus, the no. of neutrons in fluorine is 19 – 9 = 10. Note: proton no., nucleon no. & no. of neutrons all must be positive integers (whole numbers) Nucleon number or mass number

14. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules X A Z Atomic symbol Nucleon number or mass number Proton number or atomic number Proton no.Nucleon no.Isotopes Pre-testExampleExercise Past year Question In a neutral atom the no. of protons is equal to the no. of electrons, so the proton no. also indicates the no. of electrons present in the atom. For example, the proton no. of nitrogen is 7. This means that each neutral nitrogen atom has 7 protons and 7 electrons. Proton number or atomic number

15. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules X A Z Atomic symbol Nucleon number or mass number Proton number or atomic number Proton no.Nucleon no.Isotopes Pre-testExampleExercise Past year Question The X represent of atom of an element. For example atom of uranium with nucleon numbers of 235 and proton numbers of 92. So the uranium can be denoted as:- U 235 92 Atomic symbol

16. Ex: Number of protons = proton number = 13 Number of neutrons = nucleon number – proton number = 27 - 13 = 14 Number of electron= proton number – charge carried by species = 13 – ( +3) = 10

17. Q: determine the number of proton, neutron and electron in the following species.

18. solution Number of protons = proton number = 38 Number of neutrons = nucleon number – proton number = 90 – 38 = 52 Number of electron= proton number (species is neutral) = 38 Sr 90 38 Sr

19. Number of protons = proton number = 17 Number of neutrons = nucleon number – proton number = 35 – 17 = 18 Number of electron= proton number – charge carried by species = 17 – (-1) = 18 35 17 Cl -

20. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules 1.State the sub-atomic particles of an atom? 2.Define proton numbers and nucleon numbers? 3.What is isotopes? Use hydrogen as an example. ANSWER 1.Protons, electrons & neutrons 2.Proton numbers = number of protons in the nucleus of an atom Nucleon numbers = total no. of protons & neutrons in atom 3.Isotopes = atoms that have the same no. of protons but have different nucleon numbers.

21. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules 1.Give the number of protons, neutrons and electrons in each of the following species: (a) (b) (c) ANSWER * Recall that the superscript denotes nucleon number & the subscript denotes proton number. (a) Proton number = 8, so there are 8 protons. Nucleon number = 17, so the number of neutrons is 17-8 = 9. The number of electrons is the same as the number of protons, that is 8. (b) Proton numbers = 80, so there are 80 protons. Nucleon number = 199, so the number of neutrons is 199-80 = 119. The number of electrons = 80. (c) Number of protons = 80. Number of neutrons, 200-80 = 120. Number of electrons = 80. Hg O 17 8 199 80 200 80

22. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules 1.Isotopes of an element are having A the same nuclear charge B similar physical properties C the same number of neutrons D the same relative abundance 2. All the following statements are true EXCEPT A Nucleus is the positively charged centre of an atom B Protons number indicates the number of protons in an atom C Isotopes are atoms of the same element but with different nucleon number D Nucleon number is the total number of electrons and protons in an atom ans

23. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules 1.Isotopes of an element are having A the same nuclear charge B similar physical properties C the same number of neutrons D the same relative abundance 2. All the following statements are true EXCEPT A Nucleus is the positively charged centre of an atom B Protons number indicates the number of protons in an atom C Isotopes are atoms of the same element but with different nucleon number D Nucleon number is the total number of electrons and protons in an atom next

24. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules 3.Which of the following is a pair of isotopes? A 138 58 J and 138 60 K B 74 32 L and 75 33 M C 83 36 N and 84 36 O D 235 92 P and 239 94 Q 4.Which of the following species has 24 neutrons? A 24 Mg B 45 Sc C 51 V D 52 Cr ans

25. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules 3.Which of the following is a pair of isotopes? A 138 58 J and 138 60 K B 74 32 L and 75 33 M C 83 36 N and 84 36 O D 235 92 P and 239 94 Q 4.Which of the following species has 24 neutrons? A 24 Mg B 45 Sc C 51 V D 52 Cr next

26. Objective: At the end of the lesson, you should be able to: 2) Define proton number, nucleon number and isotopes TOPIC 1: MATTER SUB TOPIC: Atoms and Molecules WELL DONE! Try some past paper questions