1.
State what is meant by an atom. [1]
JD SCIENCE
The nature of substances and chemical reactions
Answer all questions. Show working. Answers are in a separate file on the Worksheets page — do not look at them until you have finished.
2.
State what is meant by a proton. [1]
3.
State what is meant by a neutron. [1]
4.
State what is meant by an electron. [1]
5.
State what is meant by an isotope. [1]
6.
State what is meant by the periodic table. [1]
7.
State what is meant by a Group 1 metal. [1]
8.
State what is meant by a Group 7 element. [1]
9.
State what is meant by a mixture. [1]
10.
State what is meant by a compound. [1]
11.
Owain is asked about an atom in a WJEC Chemistry paper.
(a) Describe an atom. [2]
(b) Explain why an atom is important in this topic. [3]
12.
Owain is asked about a proton in a WJEC Chemistry paper.
(a) Describe a proton. [2]
(b) Explain why a proton is important in this topic. [3]
13.
Owain is asked about a neutron in a WJEC Chemistry paper.
(a) Describe a neutron. [2]
(b) Explain why a neutron is important in this topic. [3]
14.
Owain is asked about an electron in a WJEC Chemistry paper.
(a) Describe an electron. [2]
(b) Explain why an electron is important in this topic. [3]
15.
Owain is asked about an isotope in a WJEC Chemistry paper.
(a) Describe an isotope. [2]
(b) Explain why an isotope is important in this topic. [3]
16.
Owain is asked about the periodic table in a WJEC Chemistry paper.
(a) Describe the periodic table. [2]
(b) Explain why the periodic table is important in this topic. [3]
17.
An atom has 15 protons and 27 neutrons. Write the mass number and atomic number. [3]
18.
Calculate the relative atomic mass of an element with 75% isotope 35 and 25% isotope 37. [3]
19.
How many electrons are in a 15+ ion of this element if it is in Group 1? [3]
20.
A shell holds 2n² electrons. How many in the 3rd shell? [3]
21.
20 g of carbon-12 contains 1 mole. How many atoms? [3]
22.
Write the electronic structure of an element with 17 electrons. [3]
23.
Owain carries out the flame-test practical for metal ions. This is a typical WJEC required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
24.
Owain carries out paper chromatography of inks. This is a typical WJEC required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
25.
Owain carries out separating rock salt (sand and salt). This is a typical WJEC required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
26.
Owain carries out investigating the reaction of Group 1 metals with water (demonstration). This is a typical WJEC required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
27.
Compare an element with a compound. [4]
28.
Compare Group 1 with Group 7. [4]
29.
Compare a mixture with a compound. [4]
30.
Compare the plum-pudding model with the nuclear model. [4]
31.
Apply your knowledge of a Group 1 metal to this situation: outer electron is further / more shielding [3]
32.
Apply your knowledge of a Group 7 element to this situation: chlorine is more reactive [3]