A) A mixture of different substances B) A substance made from two or more elements chemically combined C) A substance that can always be separated physically D) A substance made up of atoms with the same number of protons
A) A compound B) A molecule of water C) An atom D) A mixture
A) Cr B) Co C) C D) Ca
A) All chemical symbols contain two capital letters B) Chemical symbols are written only in lowercase C) The first letter is always capitalised D) The second letter is always capitalised
A) na B) Na C) nA D) NA
A) The physical state of the element B) The number of protons in its atoms C) The number of neutrons in its atoms D) The number of molecules present
A) Neon B) Argon C) Helium D) Oxygen
A) Cl B) C?l C) Cl? D) Cl?
A) In order of atomic number B) In order of density C) In order of melting point D) In alphabetical order
A) Carbon B) Water C) Sodium chloride D) Carbon dioxide
A) A substance containing only one type of atom B) A single atom C) A substance containing two or more different elements chemically combined D) A physical mixture of substances
A) A ratio determined by the size of the sample B) Any ratio C) A fixed ratio D) A changing ratio
A) The mass of the whole sample only B) The colour of the compound C) The temperature at which it forms D) The types and relative numbers of atoms present
A) OH B) H?O C) H?O? D) HO?
A) N?H? B) NH? C) NO? D) NH?
A) Mixture B) Covalent compound C) Ionic compound D) Elemental molecule
A) Ionic compound B) Metallic element C) Alloy D) Covalent compound
A) Three B) One C) Four D) Two
A) Carbon dioxide B) Carbon monoxide C) Carbon trioxide D) Cobalt dioxide
A) It contains only one element B) Its elements are chemically combined and cannot be separated by physical methods C) Its components retain all their original properties and can be separated by filtering D) Its elements are mixed in any proportion
A) On the left-hand side B) On the right-hand side C) Above the arrow D) Below the arrow
A) Reactants B) Mixtures C) Catalysts D) Products
A) Is heated by B) Is equal to in mass only C) Dissolves in D) Produces or forms
A) Both sides always B) The left-hand side C) The right-hand side D) Neither side
A) Solution B) Steam C) Solid D) Salt
A) A pure liquid B) Aqueous solution C) A solid D) A gas
A) (s) B) (l) C) (g) D) (aq)
A) To make the equation shorter B) To show that atoms disappear during reactions C) To make the products heavier than the reactants D) To show the same number of each type of atom on both sides
A) Formation of mixtures B) Conservation of mass C) Change of state D) Conservation of temperature
A) Al + 3CuO ? Al?O? + 3Cu B) 2Al + 3CuO ? Al?O? + 3Cu C) 2Al + CuO ? Al?O? + Cu D) Al + CuO ? Al?O? + Cu
A) Multiple proportions B) Definite proportions C) Conservation of energy D) Conservation of mass
A) Decomposition reaction B) Combustion reaction C) Addition reaction D) Neutralization reaction
A) 3H2SO4 + 2Al(OH)_3 --> Al2(SO4)_3 + 8H2O B) 3H2SO4 + 2Al(OH)_3 --> Al2(SO4)_3 + 6H2O C) H2SO4 + Al(OH)_3 --> Al2(SO4)_3 + 2H2O D) H2SO4 + Al(OH)_3 --> Al2(SO4)_3 + H2O
A) 2;4;1 B) 4;2;1 C) 1;2;4 D) 4;1;2
A) 2;25;16;18 B) 18;16;25;2 C) 25;16;2;18 D) 2:15;18;16
A) 7;4;2;6 B) 4;6;7;2 C) 2;7;4;6 D) 7;4;6;2
A) 3;5;1;4 B) 5;1;3;4 C) 1;5;3;4 D) 4;3;5;1
A) 2;1;2;1;1 B) 1;2;2;1;1 C) 2;2;1;1;1 D) 2;2;1;2;1
A) 2;3;2;3 B) 2;2;3;3 C) 3;3;2;3 D) 3;3;3;2
A) 4;3;6;2 B) 4;3;2;6 C) 6;2;3;4 D) 4;3;3;6
A) 2;3;4 B) 4;2;3 C) 4;3;2 D) 3;2;4
A) 4;11;2;8 B) 4;8;2;11 C) 11;4;2;8 D) 4,;8;2;11
A) CxHy + x+y/4O2 --> xCO2 + y/2H2O B) CxHy + y/4O2 --> xCO2 + y/2H2O C) CxHy + x+y/2O2 --> xCO2 + y/4H2O D) CxHy + x+y/4O2 --> xCO + y/2H2O |