AQA Chemistry A Level Exam

AQA Chemistry A Level Exam What is the relative mass and charge on a proton? - correct answer Mass 1 charge +1 What is the relative mass and charge on a neutron? - correct answer Mass 1 Charge 0 What is the relative mass and charge on an electron? - correct answer Mass 1/2000 Charge -1 What is the mass number? - correct answer The total number of protons and neutrons in the nucleus of an atom What is the Atomic (proton) number? - correct answer This is the number of protons in the nucleus of an atom and is used to identify an element What are Ions? - correct answer Ion have different numbers of protons and electrons. Negative ions have more electrons than protons and positive ions have fewer electrons than protons. What are isotopes? - correct answer Isotopes of an element are atoms with the same number of protons but different numbers of neutrons describe Thomson's model of the atom. - correct answer Thomson's model of the atom was like a 'plum pudding' with a positively charged pudding (solid sphere) that contained negatively charged particles (electrons). What was found in Rutherford's gold foil experiment? - correct answer When alpha particles were fired at a thin gold sheet, most of them passed straight through with a very small number deflected straight back. What was Rutherford's new nuclear model for the atom? - correct answer A tiny positively charged nucleus at the centre, surrounded by a cloud of negative electrons. Most of the atom is empty space. What did Bohr's atom model show? - correct answer Electrons only exist in fixed orbits and not anywhere in between. Each Shell has a fixed energy. When an electron moves between shells, electromagnetic radiation is emitted or absorbed. Because the energy of the shells is fixed, the radiation will have a fixed energy. What difference is found between the original Bohr atom model and the refined Bohr model? - correct answer Scientists discovered that not all electrons in a shell have the same energy, so it was refined to include sub shell's. What is relative atomic mass? - correct answer The average mass of an atom of an element compared to one twelfth of the mass of an atom of carbon 12. What is relative isotopic mass? - correct answer Relative isotopic mass is the mass of an atom of an isotope of an element on a scale where an atom of Carbon-12 is exactly 12. Calculating relative atomic mass - correct answer relative atomic mass = isotopic masses x percentages/total percentage What is relative molecular mass? - correct answer The average mass of an entity compared to one twelfth of the mass of an atom of carbon 12. What is the equation used to calculate the number of moles of any substance? - correct answer Number of moles = mass(g)/ mass of one mole (mol) What are the 5 stages in mass spectrometery? - correct answer vaporisation, ionisation, acceleration, deflection, and detection What happens during the vaporisation stage of mass spectrometry? - correct answer The sample is turned into a gas using an electrical heater in a vacuum.