Question

activity: periodic table
use each clue below to determine the identity of the element on the periodic table.
clues:

1. symbol au.
2. the most reactive nonmetal.
3. atomic number of 12.
4. an alkali metal in period 4.
5. the most abundant element in air.

hint: it has an atomic number of 7.

1. a metal with 3 valence electrons, used in cans.
2. a period 3 element that will not react naturally.
3. has 5 valence electrons and is in period 3.
4. the most reactive metal.
5. a period 1 element used to make balloons float.
6. the only nonmetal in group 1.
7. responsible for the smell of rotten eggs.

hint: it has 16 protons.

1. has an atomic number that doubles silicons.
2. the first element in the group of rare earth metals.
3. a group 12 metal that was once used in thermometers,

but is now known to be poisonous.

1. has 3 valence electrons and 4 energy levels.
2. the only metalloid in period 3.
3. the only metalloid with 3 valence electrons.
4. the alkali metal that makes up table salt.
5. its most common isotope has 5 neutrons.

Explanation:

1. Gold has the chemical symbol Au.
2. Fluorine is the most reactive non - metal.
3. Magnesium has an atomic number of 12.
4. Potassium is an alkali metal in period 4.
5. Nitrogen is the most abundant element in air and has an atomic number of 7.
6. Aluminium is a metal with 3 valence electrons and is used in cans.
7. Argon is a period 3 element that is inert (does not react naturally).
8. Phosphorus has 5 valence electrons and is in period 3.
9. Francium is the most reactive metal.
10. Helium is a period 1 element used to make balloons float.
11. Hydrogen is the only non - metal in group 1.
12. Sulfur is responsible for the smell of rotten eggs and has 16 protons.
13. Germanium has an atomic number (32) that doubles silicon's (16).
14. Lanthanum is the first element in the group of rare earth metals.
15. Mercury is a group 12 metal that was once used in thermometers and is poisonous.
16. Gallium has 3 valence electrons and 4 energy levels.
17. Silicon is the only metalloid in period 3.
18. Boron is the only metalloid with 3 valence electrons.
19. Sodium is the alkali metal that makes up table salt (as part of NaCl).
20. Boron's most common isotope (B - 10) has 5 neutrons (atomic number 5, mass number 10, neutrons = mass number - atomic number = 10 - 5 = 5).

Answer:

1. Gold
2. Fluorine
3. Magnesium
4. Potassium
5. Nitrogen
6. Aluminium
7. Argon
8. Phosphorus
9. Francium
10. Helium
11. Hydrogen
12. Sulfur
13. Germanium
14. Lanthanum
15. Mercury
16. Gallium
17. Silicon
18. Boron
19. Sodium
20. Boron