Year 8 Science · Unit 2 · Lesson 9
Foundation Worksheet
Learning Goals
True or False? Fix the false ones
Circle T or F for each statement. If the statement is false, rewrite it correctly on the line below.
A sodium ion (Na⁺) has a different number of protons from a neutral sodium atom.
Correct it:
An ion is a brand-new element, different from the atom it formed from.
Correct it:
Na⁺ has one more electron than a neutral sodium atom.
Correct it:
A cation is a positively charged ion formed when an atom loses electrons.
Correct it:
An anion has gained electrons, so it has an overall negative charge.
Correct it:
Odd one out
Circle the item that does not belong in each group. Then explain why it doesn't fit.
| # | Group | Your answer (odd one + reason) |
|---|---|---|
| 1 | Na⁺ Mg²⁺ Al³⁺ O²⁻ | |
| 2 | Na⁺ Mg²⁺ K⁺ Cl⁻ | |
| 3 | Lost electrons Positive charge Cation Gained electrons | |
| 4 | Lost 1 electron Charge = +1 More protons than electrons Gained 1 electron |
1. Chlorine (Cl) has 17 protons. When it forms an ion, it gains one electron to become Cl⁻. How many protons and electrons does Cl⁻ have? Is Cl⁻ a cation or an anion?
2. A magnesium atom forms the ion Mg²⁺. How many electrons did it lose, and is Mg²⁺ a cation or an anion? Explain your answer.
Wrap Up
In one sentence, what was the main idea of this lesson?