6072774
Description
Flashcards by Mel Hughes, updated more than 1 year ago
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Created by Mel Hughes
over 8 years ago
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| Question | Answer |
| How can you tell that the compound H2O has covalent bonds? | It's made of non metals |
| Which of these compounds have ionic bonding? Kbr, Hcl, H2S, Na2O, Cl2O, MgO | KBr, Na2O, MgO |
| Explain what happens to the atoms of the elements when lithium reacts with fluorine | Lithium atoms lose an electron to form a lithium ion that has a positive charge or Li+, fluorine atoms gain an electron to form a fluorine ion that has a negative charge or F- |
| Why is the formula of sodium chloride NaCl but magnesium chloride is MgCl2? | Sodium ions have a single positive charge -They are Na+, and magnesium ions have a double positive charge: they are Mg2+ (chloride ions have a single negative charge and are Cl-) |
| Write the formula for each of these compounds: calcium fluoride, sodium sulfate, magnesium nitrate, copper (II) chloride, iron(III) hydroxide | CaF2, Na2SO4, Mg(NO3)2, CuCl2, Fe(OH)3 |
| How are the atoms arranged in a metal? | In a giant structure, closely packed together in layers with a regular pattern |
| What forces hold metal atoms in place in their giant structures? | Electrostatic forces between positive (metal) ions and delocalised electrons |
| What is a compound? | A substance made of two or more elements that have reacted together or that are chemically bonded together |
| Which electrons in an atom are involved in bonding? | Outer electrons (electrons in the highest occupied energy level or outer shell). |
| What happens to the electrons in atoms when ionic bonds are formed? | They are transferred or metal atoms lose electrons and non-metal atoms gain electrons |
| What happens to the electrons in atoms when covalent bonds are formed? | They are shared. For each covalent bond one pair of electrons is shared |
| Why do the elements in group 1 form ions with a single positive charge? | They lose their one outer electron (one electron in the highest occupied energy level or outer shell) |
| Why do the elements in group 7 form ions with a single negative charge? | They gain one electron so their outer shell has eight electrons or so they have the structure of a noble gas |
| Which of the following substances are made of molecules? KCl, H2O, C2H6, MgO, CO2, NaNO3 | H2O, C2H6, CO2 |
| Why can the structure of a metallic element like copper be represented by lots of small spheres the same size packed together? | The atoms in copper are all the same size, they are spherical, they are closely packed together (in a giant structure) |
| Write the correct formula for each of the following: lithium chloride, sodium oxide, calcium fluoride, magnesium hydroxide, sodium sulfate, calcium nitrate | LiCl, Na2O, CaF2, Mg(OH)2, Na2SO4, Ca(NO3)2 |
| Why do ionic compounds have giant structures? | The attractive forces between oppositely charged ions act in all directions, so the ions pack closely together in a regular arrangement (lattice), ions are very small so a crystal contains many ions |
| Explain why silicon (in group 4) has a giant structure | They form 4 covalent bonds each silicon atom can join to 4 others, the bonds are strong; this continues so that a giant structure is formed |
| Explain how the atoms in a piece of sodium metal are held together | The outer electrons delocalise, leaving a lattice of positive ions; the electrostatic forces are strong, and these hold the ions in position |
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