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Year 8 Chemistry
Year 8 Chemistry Revision
| Question | Answer |
|---|---|
| Is an electron :a) negatively charged b) neutrally charged c) positively charged | a) Electrons are negatively charged |
| Is a neutron a) negatively charged b) neutrally charged c) positively charged | b) Neutrons are neutrally charged |
| Is a proton a) positively charged b) neutrally charged c) positively charged | c) Protons are positively charged |
| Do metals: a) conduct electricity b) not conduct electricity | a) Metals conduct electricity |
| Are metals maliable? | Yes, metals are maliable |
| Are metals ductile? | Yes, metals are ductile |
| Are metals brittle? | No, metals are not brittle. |
| Do metals conduct heat? | Yes, metals conduct heat |
| Are metals located: a) on the left side of the periodic table b) in a column down the right side of the periodic table c) across a few groups on the right hand side of the periodic table | a) Metals are located on the left side of the periodic table |
| The non-metals are :a) on the left side of the periodic table b) in a column down the right side of the periodic table c) across a few groups on the right hand side of the periodic table | c) the non-metals are across a few groups on the right hand side of the periodic table |
| True or False: Elements contain only one type of atom? | True. Elements are made of only one type of atom |
| True or False: Compounds contain only one type of atom. | False. Compounds are made of more than one type of atom, in a fixed ratio. EG H20 is a compound which contains twice as much hydrogen as oxygen |
| True or False: The production of a gas is a sign of a chemical reaction. | True. The production of a gas does show a chemical reaction has occured |
| Name 2 signs of a chemical reaction | The signs of a chemical reaction are:* change in mass* change in temperature* production of a gas* formation of a precipitate* permanent change in colour* production of light |
| What is a precipitate? | A precipitate is a solid formed when 2 liquids are mixed. It is a sign that a chemical reaction has occurred. |
| What is an element's atomic number? | An atom's atomic number is the number of protons in an atom's nucleus. |
| What is an element's mass number? | The mass number is the number of protons + neutrons in an atom's nucleus. |
| In a atom, how many electrons are there compared with the number of protons? | In a n atom, the number of electrons is EQUAL to the number of protons. |
| A chemical that increases the rate of a reaction without being consumed by the reaction is called? | A catalyst |
| True or False: Increasing temperature decreases the speed of a chemical reaction | False. Higher temperature increases reaction speed |
| True or False: Decreasing the size of particles decreases the speed of a chemical reaction. | False. Smaller particles react faster. |
| Does stirring increase the speed of a chemical reaction? | Yes, stirring increases the rate of a chemical reaction. |
| Can a physical change be easily reversed? | Yes |
| Can a chemical change be easily reversed? | Not ususally |
| What is a sign of a chemical change? | Permanent change in colour Production of a gas Generation of light, heat or absence of heat |
| How do we write a chemical equation? | reactants --> products |
| What is the Periodic Table? | a list of the elements in order of increasing atomic mass. The groups show the properties. |
| How are the groups shown on the Periodic table? | There are 18 groups, given as columns |
| How are the periods arranged on the Periodic table? | There are 7 periods, given as rows |