Photo AI
Elements are made of atoms - AQA - GCSE Chemistry - Question 1 - 2017 - Paper 1
Question 1
Elements are made of atoms. Table 1 shows the atomic numbers and mass numbers of three atoms. Table 1 | Atom | Atomic number | Mass number | |------|-------------... show full transcript
Worked Solution & Example Answer:Elements are made of atoms - AQA - GCSE Chemistry - Question 1 - 2017 - Paper 1
Step 1
Suggest, in terms of the number of subatomic particles, why the atomic numbers of the three atoms are the same.
Answer
The atomic numbers of the three atoms are the same because they each contain the same number of protons. Since the atomic number is defined as the number of protons in an atom's nucleus, and all three atoms share the same atomic number of 12, they must therefore have 12 protons each.
Step 2
Explain, in terms of the number of subatomic particles, why the mass numbers of the three atoms are different.
Answer
The mass numbers of the three atoms are different due to the varying number of neutrons in their nuclei. The mass number is the sum of protons and neutrons, so while all three atoms have 12 protons, they have different numbers of neutrons. Specifically, Atom 1 has 12 neutrons (mass number 24), Atom 2 has 13 neutrons (mass number 25), and Atom 3 has 14 neutrons (mass number 26).
Step 3
Step 4
Step 5
Step 6
Describe and explain the changes seen during the reaction.
Answer
During the reaction, two main changes occur. First, when copper carbonate is added to sulfuric acid, the solution turns from clear to cloudy, indicating a chemical reaction. The mass of the reactants decreases, which can be attributed to the production of carbon dioxide gas that escapes into the atmosphere. The copper carbonate may change from its initial green color to a different form or may dissolve, creating bubbles or fizzing as carbon dioxide is released. The testing of limewater indicates the presence of carbon dioxide, confirming the chemical reaction.