1. 29 February 2016 Today’s Title: CW: Isotops Learning Question: What is an isotope ? Starter – http://www.bbc.co.uk/learningzone/clips/ato ms-and-isotopes/10662.html

2. Key words… Atom Proton Electron Neutron Mass number Atomic number

3. Atoms Atoms are made of three types of sub-atomic particle: – neutrons – protons – electrons In the nucleus Orbiting around the nucleus nucleus electron neutron

4. Atoms Atoms are made up of two main parts, the nucleus and orbiting electrons. Electrons can be lost or gained and this forms charged particles - ions The nucleus contains two types of particles called protons and neutrons As protons, neutrons and electrons are the building blocks of atoms they're called sub-atomic particles

5. Mass Number Sometimes the number of neutrons in an atom can vary. The mass number of an atom is the total number of protons and neutrons in the nucleus

6. Atomic Number The atomic number of an atom is the number of protons (or electrons) in an element

7. Quick questions 1.What does the atomic number of an element tell you? 2.What does the mass number of an element tell you?

8. 1What does the atomic number of an element tell you? A:The number of protons in the nucleus. 2What does the mass number of an element tell you? A:The total number of protons and neutrons.

9. Isotopes Two atoms of the same element will always have the same atomic number The mass numbers can change if they contain different numbers of neutrons Atoms of a single element that have different numbers of neutrons are called isotopes

11. IsotopeSymbolPNE Protium 101 Used as fuel, for hardening margarine. Deuterium 111 Used in heavy or deuterated water, solvent Tritium 121 Radioactive, Used in H-bombs, glow in the dark paints Isotopes of hydrogen

12. ProtiumDeuterium Tritium 1 proton, 0 neutron, 1 electron 1 proton, 1 neutron, 1 electron 1 proton, 2 neutron, 1 electron

13. Quick questions 3. A helium nucleus has 2 protons and 2 neutrons. Write down the symbol for the helium nucleus, showing the atomic number and mass number 4. The symbol for a beryllium nucleus is Be. How many of the following particles does it contain? a.Protons b.neutrons

14. Your task Complete questions 5-8 from page 253 of your textbook.

15. 3A helium nucleus has 2 protons and 2 neutrons. Write down the symbol for the helium nucleus, showing the atomic number and mass number. A: 4 2 He. 4The symbol for a beryllium nucleus is 9 4 Be. How many of the following particles does it contain? a protons A:4 protons bneutrons. A:5 neutrons

16. 5. A:a4, 5, 4 bBeryllium, boron, beryllium c 10 4 Be, 10 5 B, 9 4 Be 6An atom of fluorine has 9 protons and 10 neutrons. Write down the symbol for a fluorine nucleus, showing the atomic number and nucleon number. A: 19 9 F 7Sam says that as two different atoms have the same mass number, they must be isotopes. Is Sam correct? Explain your answer. A:No, isotopes have the same number of protons but different numbers of neutrons so they actually have different mass numbers.

17. 8Hydrogen has three isotopes, hydrogen-1, hydrogen-2 and hydrogen-3. Explain what an isotope is and the similarities and differences between these three isotopes. A: Isotopes contain the same number of protons but different numbers of neutrons – they have the same atomic number. All three isotopes of hydrogen contain one proton. Hydrogen-1 does not contain any neutrons. Hydrogen-2 contains one neutron. Hydrogen-3 contains two neutrons.