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FlashCards por Oliver Faragher, atualizado more than 1 year ago
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Criado por Oliver Faragher
mais de 6 anos atrás
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| Questão | Responda |
| What is an element? | A substance that cannot be broken down chemically |
| How many elements are there? | 115 (Textbook says around 100) |
| What is an exothermic and an endothermic reaction? | Exothermic = A reaction that gives off heat Endothermic = A reaction that takes in heat |
| What does "ide" represent when at the end of a compound name? e.g Sodium ChlorIDE | The two elements (sodium and chlorine) are joined together with no other elements involved |
| What does "ate" represent when at the end of a compound name? e.g Potassium Nitrate | The compound has the two elements (potassium and nitrogen) joined together along with the third element of oxygen |
| What happens when two or more atoms join? | They form a molecule |
| Balance the following equation Mg + O2 = MgO | 2Mg + O2 = 2MgO2 (Add a two in front of the magnesium and product) |
| Why do we balance equations? | To guarantee that it follows the law of conservation of mass |
| What are mixtures? | Solutions containing two or more chemicals not chemically joined |
| What methods can we use to separate mixtures? | Filtration, Crystallization, Simple distillation, fractional distillation and chromotography |
| What is fraction distillation used to separate? | More than two liquids with different boiling points. |
| How does fractional distillation work? | The mixture is heated and then the various different components evaporate and then condense again on tubes that become gradually cooler the further up you go |
| Fractional distillation diagram | |
| What did the Greek philosopher theorize in 400BC | He described materials being made of small particles called atoms which could not be divided |
| What did John Dalton suggest? | He said that atoms were spherical shapes, like billiard balls, that could not be divided |
| What did J.J Thompson discover? | He discovered the existence of electrons and proposed that negative electrons were embedded in a positively charged pudding shaped atom |
| What did Ernest Rutherford's team discover? | Through the gold leaf experiments, where they sent a beam of alpha particles through a gold leaf, they discovered that the atom had a positively charged nucleus and they created the nuclear model |
| What did Niels Bohr discover? | Niels Bohr create the Bohr model (GCSE one) and stated that electrons were placed on energy levels at set distances |
| What did James Chadwick discover? | He discovered the existence of neutrons in the nucleus |
| What are the relative atomic masses of protons, neutrons and electrons? | Proton = 1 Neutron = 1 1 Electron = ------ (0) 1836 |
| What is the normal radius of atoms and how does this get bigger? | The normal radius is 1nm It gets larger the further down the table you go (the more shells you get) |
| Which number is always bigger in an element, the relative mass or the atomic number? | Relative mass |
| How do you calculate the number of protons OR electrons | Use the atomic number |
| How do you calculate the number of neutrons? | Subtract the atomic number from the atomic mass |
| What are the charges of protons and electrons? | Proton = +1 Electron = -1 |
| What is are isotopes? | Atoms with different numbers of neutrons |
| What is the formula for relative abundance? | Ar = (mass of first isotope x % of isotope) x (mass of second isotope x % of isotope) All are divided by 100 |
| What do column numbers in the periodic table represent? | Number of valence (outer shell) electrons |
| What do the row numbers represent in the periodic table? | Number of shells |
| How many electrons can each shell hold (in order) | 2, 8 , 8 , 2 |
| What forms when you react group 1 and 7? | A salt |
| What is the proper word for group 8 being non-reactive? | Inert |
| What did Mendeleev do that previous table developers had not done? | He arranged based on properties and he left gaps based on predictions for future elements |
| What are the main properties of metals? | Lustrous, hard, high density, high strength, high melting/boiling point, good heat conductors, good electrical conductors |
| What are the main properties of non-metals? | Dull, Soft/brittle, low density, low melting point/boiling point, poor-no thermal conduction, poor-no conductors of electricity |
| What happens when you react a metal and non-metal? | The metal will lose electrons (becoming a positive ion) and the non-metal will gain electrons (becoming a negative ion) |
| What are outer electrons called? | Valence Electrons |
| What makes an atom stable? | A full outer shell |
| What happens if an atom has an unstable number of electrons (3/4/5)? | It will share electrons with another element (any more than this and it gains electrons and any less and it loses) |
| How do boiling points change as you go down group 8? | They decrease |
| What is the key property of any group 1 element? | It is highly reactive with water |
| What gas do group 1 metals give off when they react with water? | Hydrogen |
| What is an ion? | An atom with and positive or negative charge (it has lost/gained electrons) |
| What happens to reactivity as you go down group 7? | It decreases |
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