Symbols, numbers and isotopes
Answers are for parents and teachers.
1
Write from memory the symbols of sodium, potassium, copper and iron, then check them.
Na, K, Cu and Fe.
2
An atom is written ³⁹₁₉K. How many protons, neutrons and electrons does it have?
19 protons, 20 neutrons and 19 electrons.
3
With an adult, look at a fertiliser bag or a picture of one. Which three elements does NPK stand for, and what does each do for plants?
Nitrogen for green leaves, phosphorus for strong roots, potassium for healthy growth.
4
An atom has Z = 15 and A = 31. Write how many protons, neutrons and electrons it has.
15 protons, 31 − 15 = 16 neutrons and 15 electrons.
5
Write one sentence to explain to a friend what an isotope is. Use hydrogen as your example.
Isotopes are atoms of one element with different numbers of neutrons; hydrogen has protium (0 neutrons), deuterium (1) and tritium (2).