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27 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Element |
Substance that compromises of one type of atom |
E.g. Helium, Hydrogen |
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Mixture |
Substance made of different elements which aren't chemically bonded |
E.g. Air |
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Compound |
Substance which compromises of two or more atoms which are chemically bonded together. |
Copper sulfate |
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What are electrons arranged into? |
They are arranged into shells, around the nucleus. Outer shells contain more electrons than inner shells. |
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How is an element defined? |
It is defined by the number of protons in its nucleus. |
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What do atoms have inside them that are the same? |
An atom has the same number of electrons as protons they overall have no charge. |
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What happens when we move electrons from an atom? |
We would create an ion (charged) |
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Rule of Atomic shell structure |
There should be no more than two electrons in the first shell. There should be no more than 8 electrons in the second shell. There should be no more than 8 electrons in the third shell. |
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How to decide whether something is metal or non-metal? |
- Observe how it looks/feels - See if it can conduct electricity - put the object in a circuit - See if it is magnetic |
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What are semi-metals (metalloids)? |
They have some properties which are similar to metals. |
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What does it mean when lime water turns cloudy? |
There is a presence if carbon dioxide. |
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What happens when there is hydrogen in a test tube and you place a lit splint inside it? |
You would hear a squeaky pop. |
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What happens when you heat elements? |
Oxidation happens. |
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What happens when you heat compounds? |
They decompose. |
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Test if substance is element or compound. |
1. Weigh substance and take measurement 2. Place substance in a test tube with spatula. 3. Grab test tube with test tube holder. 4. Hold it over a bunsen burner for a few seconds. 5. If substance burns completely, it's an element. If not it's a compound. |
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What do numbers in front of formulae show? |
They show how many molecules of a substance react or are produced. E. G. 2H2O means two molecules of water. |
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What happens if there is a presence of gas during a reaction? |
It means mass has been lost. |
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What do we call when chemical reactions release energy? |
It is an exothermic reaction. |
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What do we call a chemical reaction where energy is transferred to them from their surroundings? |
It's an endothermic reaction. |
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Why do we need energy for chemical reactions? |
It is needed to break bonds as per in reactants. |
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What happens when bond breaks during chemical reaction? |
Energy gets absorbed. (Endothermic) |
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What happens when bonds form in chemical reactions? |
Energy is released (exothermic). |
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What do we call a reaction between an acid and alkali? |
A neutralisation reaction. |
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Where does aerobic respiration happen? |
It happens in the mitochondria of cells. |
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What is aerobic respiration? |
Aerobic respiration is respiration which uses oxygen and glucose to create energy. |
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What is anaerobic respiration? |
It is respiration which doesn't require oxygen. It is less efficient. |
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