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Descrição
FlashCards por michelegasparro1, atualizado more than 1 year ago
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Criado por michelegasparro1
quase 9 anos atrás
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| Questão | Responda |
| What is Newlands' Law of Octaves? | every eighth element had similar properties. |
| Why was Newlands' work criticised? | - the groups contained elements that didn't have similar properties. - metals and non-metals were mixed up. - no gaps were left for undiscovered elements. |
| How did Mendeleev order the elements? | he ordered the elements in order of atomic mass. |
| What did Mendeleev do, that Newlands' didn't do? | he left gaps in order to keep elements with similar properties in the same groups. |
| What do the group 1 elements consist of? | alkali metals. |
| As you go down the group... | - the elements become more reactive because the the outer electron is more easily lost because it is further from the nucleus. - the elements have lower melting/boiling points. |
| What type of bond do the alkali metals form? | ionic bonds with non-metals. |
| Why are the alkali metals keen to lose their outer electron? | to form a +1 ion. |
| Alkali metals react with water to produce... | hydrogen gas. |
| Alkali metals form... | hydroxides that dissolve in water that turn a solution alkaline. |
| What do the group 7 elements consist of? | the halogens. |
| As you go the group... | - the elements are less reactive because it's harder to gain an electron because the outer energy level is further from the nucleus. - higher melting/boiling points. |
| What type of bond do the halogens form? | ionic bonds with non-metals. |
| What ion is formed when the halogens bond with metals? | -1 ion called halides. |
| What can a more reactive halogen do to a less reactive one? | it can displace a less reactive halogen from an aqueous solution of it salt. |
| Transition elements are good conductors of... | heat and electricity. |
| What are the physical properties of transition elements? | dense, strong and very shiny. |
| Compared to the alkali metals, the transition elements are... | less reactive (don't react as well with water and oxygen). |
| Compared to the alkali metals, the transition elements are also... | denser , stronger, harder and have higher melting points. |
| How many ions does a transition element often have? | typically more than one. |
| With soft water, you get... | a lather. |
| With hard water, you get... | nasty scum. |
| What makes water 'hard'? | dissolved calcium and magnesium ions. |
| What happens when hard water is heated? | it forms calcium carbonate, which 'furs' up appliances. |
| What are calcium ions good for? | teeth and bones. |
| What causes temporary hard water? | hydrogencarbonate ion in calcium hydrogen carbonate. |
| What cause permanent hard water? | dissolved calcium sulphate. |
| How is temporary hardness removed? | boiling the water. |
| What happens when temporary hard water is boiled? | calcium hydrogencarbonate decomposes to form calcium carbonate (insoluble) |
| What is an ion exchange column? | the calcium/magnesium ions that are in the water are exchanged for the sodium ions in the resin. |
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