Question

activity: crossword puzzle
across:

1. i have 6 valence electrons and 16 protons.
2. i have 28 electrons when electrically neutral.
3. im the only noble gas with 2 electrons.
4. i am a halogen with 5 energy levels.
5. eat me when you have cramps in your legs.
6. i am not an alkali metal, but i am in group 1.
7. i am a metalloid that usually has 71 neutrons.
8. i am very important for healthy teeth and bones.
9. i am the 2nd most reactive metal.

down:

1. my atomic number is 47.
2. i have 26 protons.
3. my average atomic mass is 35.453.
4. i am the only liquid metal at room temperature.
5. im an alkaline earth metal used in fireworks.
6. i am a gas with 8 neutrons in my most common form.
7. i am in the fifth period and the carbon family.

Explanation:

Step1: Identify elements from clues

Use periodic - table knowledge.

Step2: Fill in crossword

Match elements to grid.

Answer:

(Actual filling of crossword requires visual - based work and cannot be fully provided here. But elements are: 1. Silver (Ag, atomic number 47), 2. Iron (Fe, 26 protons), 3. Sulfur (S, 6 valence, 16 protons), 4. Nickel (Ni, 28 electrons when neutral), 5. Chlorine (Cl, avg. atomic mass 35.453), 6. Mercury (Hg, liquid metal), 7. Helium (He, 2 - electron noble gas), 8. Iodine (I, halogen with 5 energy levels), 9. Strontium (Sr, alkaline - earth in fireworks), 10. Potassium (K, for leg cramps), 11. Hydrogen (H, in group 1, not alkali metal), 12. Oxygen (O, 8 neutrons in common form), 13. Arsenic (As, metalloid with ~71 neutrons), 14. Tin (Sn, fifth period, carbon family), 15. Calcium (Ca, for teeth and bones), 16. Calcium (Ca, 2nd most reactive metal))