Term
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Definition
| A scale that measures the acidity of a substance |
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Term
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Definition
| A very acidic substance with a pH close to zero, one or two |
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Term
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Definition
| A slightly acidic substance that has a pH of around 6 or 5 |
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Term
| What is a neutral substance? |
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Definition
| A substance that is neither acid nor base and has a pH of 7 |
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Term
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Definition
| A substance that is slightly base or alkali and has a pH of 8 or 9 |
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Term
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Definition
| A substance that is highly base or alkali and has a pH of around 12, 13 or 14 |
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Term
| How many times stronger base is pH 9 than pH 8? |
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Definition
| Ten times stronger, because the pH scale goes up using powers of ten |
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Term
| What do all acids have in common? |
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Definition
| All acids produce H+ (hydrogen positive) ions in water |
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Term
| What do most bases have in common? |
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Definition
| Most bases produce HO- (hydroxide negative) ions in water |
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Term
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Definition
| A hydrogen atom that has lost it's electron and is positively charged. |
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Term
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Definition
| A hydroxide molecule that has gained an electron |
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Term
| Why does acid produce H+ ions in water? |
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Definition
| Because a H+ ion is essentially a proton, and wants to bond and have a full valence shell, so it bonds with with water molecules, to create H3O- or a hydronium ion |
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Term
| Why do atoms want full valence shells? |
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Definition
| To become more energetically stable |
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Term
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Definition
| An atom that is charged due to gain or loss of electrons |
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Term
| How does ionic bonding work? |
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Definition
| A metal atom gives it's electrons to a non-metal atom, so that the non-metal gained enough electrons to have a full valence shell and the metal lost it's valence electrons, so it's next shell (full) becomes it's valence shell. Now, they are both oppositely charged so they attract to create a compound or molecule. |
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Term
| What two types of atoms are needed for there to be an ionic bond? |
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Definition
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Term
| Why are there sometimes two atoms of one element in an ionic bond? |
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Definition
| Because, for example, one element has one valence electron and the other has six. There will be two of the element with one, so that it can give away enough for the other element to have a full valence shell |
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Term
| What happens when an ionic bond is formed? |
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Definition
| There is a huge release of energy |
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Term
| Why is it easier for metals to give up valence electrons? |
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Definition
| They have less electronegativity than non-metals |
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Term
| What is electronegativity? |
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Definition
| How strongly an atom attracts/holds onto it's electrons |
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Term
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Definition
| A bond where atoms share electrons |
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Term
| What helps atoms form covalent bonds easily? |
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Definition
| Having similar electronegativities, so a metal and a metal can bond, unlike ionic bonding |
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Term
| What type of bond do water molecules have? |
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Definition
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