The periodic table: a first look
Answers are for parents and teachers.
1
Write the symbols of the elements from lithium (Z = 3) to neon (Z = 10) in one row, with Z under each symbol.
Li 3, Be 4, B 5, C 6, N 7, O 8, F 9, Ne 10.
2
Argon (Z = 18) has slightly heavier atoms than potassium (Z = 19). Where does each belong in the modern table, and why?
Argon comes before potassium, because the table follows Z, not mass; each lands in the column that matches its properties.
3
Name the block (s, p, d or f) of sodium, chlorine and iron.
Sodium: s block. Chlorine: p block. Iron: d block (a transition element).
4
Is the periodic table finished? Give one reason for your answer.
Answers differ. For example: scientists may still discover or make new elements, or find better ways to show the patterns.
5
A friend says hydrogen is an alkali metal because it stands above group 1A. Reply to your friend.
Hydrogen is a nonmetal gas. Its place on the left is only because of its electron arrangement.