In Figure 5, the letters A, E, G, J, X and Z show the positions of six elements in the periodic table - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2019 - Paper 1
Question 5
In Figure 5, the letters A, E, G, J, X and Z show the positions of six elements in the periodic table. These letters are not the symbols of the atoms of these elemen... show full transcript
Worked Solution & Example Answer:In Figure 5, the letters A, E, G, J, X and Z show the positions of six elements in the periodic table - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2019 - Paper 1
Step 1
Using the letters A, E, G, J and Z
(i) give the letters of the two elements that are non-metals.
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Answer
The non-metals represented in the diagram are E and J.
Step 2
(ii) give the letters of two elements in period 2.
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Answer
The two elements found in period 2 are E and J.
Step 3
(iii) give the letter of an element that normally forms an ion with a charge of +1.
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Answer
The element that normally forms an ion with a charge of +1 is J.
Step 4
(ii) All atoms of element E in this sample contain
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Answer
The correct option is A: 5 protons.
Step 5
State the electronic configuration of an atom of element X.
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Answer
The electronic configuration of element X, which has an atomic number of 18, is 2.8.8.
Step 6
Calculate the empirical formula of this compound.
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Answer
To find the empirical formula, we need to calculate the moles of each element:
Moles of A = \
ext{mass of A} \div ext{relative atomic mass of A} = 3.5 \div 7 = 0.5 , \text{mol}
Moles of G = \
ext{mass of G} \div ext{relative atomic mass of G} = 4.0 \div 16 = 0.25 , \text{mol}
The ratio of A to G = 0.5 : 0.25 = 2 : 1.
Thus, the empirical formula of the compound is A₂G.
Step 7
Complete the dot and cross diagram of a molecule of water, H₂O.
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Answer
In the dot and cross diagram of water, O has six electrons in its outer shell represented by dots. Each H atom has one electron represented by crosses. The diagram shows the sharing of electrons:
O: •• ••
H: ×
H: ×
This indicates that O shares one electron with each H to form covalent bonds.
