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Description
Flashcards by lucia larrain, updated more than 1 year ago
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Created by lucia larrain
almost 6 years ago
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| Question | Answer |
| What are elements? | Elements are substances that cannot be broken down chemically. |
| What are compounds? | Compounds are substances that contain at least two different elements, chemically combined in fixed proportions. |
| What is needed to make an element a compound? | A chemical reaction. |
| What are molecules? | Molecules are two or more atoms that join together bey sharing their electrons. |
| Give an example of a molecule? | water and oxygen. |
| Formula: balancing equations? (Of CaF2) | Group 2 - Ca Group 6 - F Ration - 2:1 |
| What are mixtures? | Mixtures are materials made up of 2 or more substances but are not chemically combined. |
| How can mixtures be separated? | Mixtures can be separated by filtration, crystallisation, distillation and chromatography. |
| What is filtration? Give an example |
Filtration is the action of filtering something
Eg. Acid+Mg(extra mg added so not everything reacts) and then filter.
Image:
Carga móvil (image/jpeg)
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| What is crystallisation? |
Crystallisation is used to separate a solid that has dissolved in a liquid and made a solution.
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Carga móvil (image/jpeg)
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| What is distillation? |
Distillation is the action of purifying a liquid by a process of heating and cooling.
Image:
Carga móvil (image/jpeg)
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| What is chromatography? |
Chromatography is
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Carga móvil (image/jpeg)
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| What is fractional distillation? | Fractional distillation is the separation of many different components by using different technics in sequence or by the same technique which includes various separations. |
| What are atoms and who found out about them ? | Atoms are small particles, they are made up of of electrons, situated in the outer shell of the atom and the protons and neutrons situated in the nucleus, every material is made of them. Democritus found out about them. |
| What is an electron and who found out about them? | An electron is a negative charge found in the outer shell of a atom. Thomson was the one to find about them. |
| What are protons and who found out about them? | Protons are particles found in the nucleus of the atoms. It was found by Thomson. |
| What is the diameter of an atom? | The diameter of an atom is of 10^-10. |
| Relative charge in: -protons -neutrons -electrons | Relative charge: -proton: + -neutron: o -electron: - |
| Relative mass: -protons -neutrons -electrons | Relativa mass: -protons: 1 -neutrons: 1 -electrons: 1/2000 |
| What happens to an atom after it loses an electron? | The atom becomes positive. |
| What is the atomic number? | The atomic number is the number that indicates how many protons and electrons the atom is made up of. |
| What is the mass number? | The mass number is the total of protons and neutrons that an atom has. |
| What are isotopes? | two or more forms of the same atom that contain equal numbers of protons but different numbers of neutrons in their nucleus. |
| Give an example of a isotope? | 35 CL 17 37 Cl 17 |
| What is the equation of a isotope? | (% of isotope 1 × mass of isotope 1) + (% of isotope 2 × mass of isotope 2) ÷ 100 |
| Group and periods in what direction does each go in the periodic table? | |
| What did Dobereiner notice in the year 1829? What where these called? | He noticed that sometimes 3 elements had similar properties. These were called 'Dobereiner triads'. |
| What did John Newlands notice in the year 1860? What where these called? | John Newlands noticed that when he put the elements in atomic weight order there was often a pattern of similar properties every eight elements. |
| What did Dmitri Mendeleev do in the 1869? | He put the elements in order of their atomic weights. And he alsodiscovered 3 new elements. |
| What happened in 1932? | The order of elements in the modern periodic table needs to be by the number of protons. |
| Properties of metals? |
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Image (binary/octet-stream)
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| Properties of non-metals? | |
| What are chemical properties? Why does metal react with oxygen? Why does metal react with acid? | Chemical properties are the reactions of metals with oxygen and acid. Metals react with oxygen to form oxides. Metals also react with acid to form salts. |
| Example of a chemical reaction? | Eg. Carbon + oxygen - carbon dioxide Carbon dioxide dissolved in water to make a mildly acidic solution. (This is what fizzy water contains). |
| What happens when a metal reacts with a gas? | The metal loses electrons and the gas gains electrons from the metal. And so it forms ions ions. |
| What happens when a non-metal reacts with a metal? | The non-metal gains electrons from the metal. The non-metal does not form a positive ion. |
| Why are the noble gases unreactive? | This is because their outer shells contain 8 electrons. And so they don't tend to transfer their electrons. |
| What happens when a gas in group 0 has a lower boiling point? | This means the atom of the element keep moving rapidly at lower temperatures. |
| what happens to the boiling points in group 0 as they go down? | The boiling points increase. |
| is it easier for the smaller atoms to move around quiker than the bigger atoms? | Yes |
| Do bigger atoms have a higher boiling point than smaller atoms? | yes |
| what group 1 elements are less dense than water? | Lithium, sodium and potassium. |
| what do group metals make when they react with water? | they make hydrogen. |
| Do metals also react with oxygen? If they do what do they form? | Yes. They form oxides. |
| What is also made when lithium, sodium and potassium react with water? | An alkali is made. |
| How many electrons do alkali metals need to lose to have a full outer shell? What does it then form? | They need to lose 1 electron. An ion forms. |
| what happens to the atom when it loses 1 electron? (Also for unit 4) | It has 1 more positive charge in its nucleus than negative electrons surrounding it. So it I now a positive ion that carries a charge of +1 |
| How are group 7 elements known as? | They are known as halogens. |
| What are halogens? How do halogens exist as? Give an example? | Halogens are non-metals. Halogens exist as pairs of atoms. eg. Cl2, F2, Br2 |
| What do halogens make when they react with metals? What do halogens make when they react with a non-metal? | They make salts. The make liquid or gases (like acids). |
| What happens to the reactivity of the halogens as you go down the group? | The reactivity goes down. |
| What are halides? | Compound of a halogen with another element or group |
| What are metal-halides? | Metal halides are compounds between metals and halogens. |
| What happens when halogens are bubbled through solutions of metal halides? | There is no reaction or there is a displacement. |
| What is a displacement reaction? | Chemical reaction in which a more reactive element displaces a less reactive element from its compound |
| Will barium be more reactive with diluted acid than magnesium? Why? | Barium will react more because its lower down group 2 and so it will lose electron more easily. |
| If bromine is bubbled through potassium chloride solution what reaction will there be? | There will be no reaction because chlorine is more reactive than bromine and so will not be displaced: |
| Do all transition metals have typical metallic properties? | Yes |
| Is the reactivity in transition metals the same as in group 1 metals? | No, they are less reactive. |
| What is a catalyst? Are you able to reuse a catalyst after a reaction? | A catalyst is an element or a compound that changes the rate of a chemical reaction without taking part in the reaction It can continue to act repeatedly. |
| What colour are the compound of group 1? What colour are the transition metals? What colour does copper become? | They are white. They are coloured. It becomes blue. |
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