No. |
Question |
Answer |
| 1 | What three particles do all atoms contain? | Protons, neutrons and electrons |
| 2 | Which particles have a mass of one unit? | Protons and neutrons. |
| 3 | What is the mass of an electron? | Almost zero. |
| 4 | What is the charge on a neutron? | No charge. (Protons are +1 and electrons -1) |
| 5 | What does the atomic number tell you about an atom? | The number of protons. |
| 6 | What does the mass number show? | The total number of protons and neutrons together. |
| 7 | Which of these two numbers is generally bigger? | The mass number. |
| 8 | What do two isotopes have in common? | 1. Both are atoms of the same element. 2. They have the same number of protons. 3. They have the same number of electrons.4. They have the same chemical properties. |
| 9 | What is different between the two isotopes? | The number of neutrons (They have different mass numbers). |
| 10 | Sodium and chlorine react together to make what compound? | Sodium chloride. |
| 11 | What sort of bonding holds this compound together? | Ionic bonding. |
| 12 | How can you tell? | It is a compound of a metal and a non-metal. |
| 13 | Is it metals or non-metals that make positive ions? | Metals make positive ions (by losing electrons). |
| 14 | What is an ionic lattice? | The arrangement of positive and negative ions that keeps positive and negative ions next to each other. |
| 15 | Is the melting point of an ionic compound low, medium or high? | High (because positive and negative ions attract each other strongly). |
| 16 | Why don't ionic compounds conduct electricity when solid? | The positive and negative ions can't move out of their fixed positions. |
| 17 | When do ionic compounds conduct electricity? | When they are molten or dissolved in water (so the ions can move). |
| 18 | What happens to the ionic compound when it conducts electricity? | It decomposes. (This is called electrolysis.) |
| 19 | What is the main difference between covalent bonding and ionic bonding? | Covalent bonding involves sharing electrons, ionic bonding involves transferring electrons. |
| 20 | What is a molecule? | A group of two or more non-metal atoms held together by covalent bonding. |
| 21 | Do substances containing molecules have a high or low melting point? | A low melting point (most are gases or liquids at room temperature e.g. H2O). |
| 22 | What is the difference between exothermic and endothermic reactions? | Exothermic reactions give out heat energy, endothermic take in heat energy (from their surroundings). |
| 23 | Does an endothermic reaction make the surroundings warmer or colder? | Colder. |
| 24 | What does the symbol Ar stand for? | Relative atomic mass. |
| 25 | What does the symbol Mr stand for? | Relative molecular mass or relative formula mass (for a molecule or for a compound). |
| 26 | If the Ar values for C = 12 and for H = 1, what is the Mr value for methane (CH4)? | Mr = 16 (12 + 1 + 1+ 1 + 1) |
| 27 | If the Ar value for N = 14, what is the Mr value for nitrogen, N2? | Mr = 28 (2 x 14) |
| 28 | If the Ar value for O = 16, what is the Mr value for ozone, O3? | Mr = 48 (3 x 16) |
01902 551509