Atomic and ionic size across the periodic table

Answer Key - Grade 10 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   Sodium's radius is 180 pm and potassium's is 220 pm (Slater). By what percent does radius grow from sodium to potassium, to 0.01%, Bo?

   22.22 %
2. 2.

   Potassium's radius is 220 pm and rubidium's is 235 pm (Slater). By what percent does radius grow from potassium to rubidium, to 0.01%, Esme?

   6.82 %

3. Read this first

   Ionic radii in pm (Shannon 1976, six-coordinate) (Shannon 1976)

   ion	electrons	radius (pm)
   O²⁻	10	140
   F⁻	10	133
   Na⁺	10	102
   Mg²⁺	10	72
   Cl⁻	18	181
   K⁺	18	138

4. 3.

   Using the table, why does size fall from O²⁻ to F⁻ to Na⁺ to Mg²⁺, Jun?

   • They each have fewer electrons, step by step
   • More protons pull the same 10 electrons
   • They lose shells each step
5. 4.

   Using the table, which 10-electron ion is largest, Kira?

   • Mg²⁺
   • Na⁺
   • O²⁻
6. 5.

   Milo says chlorine is bigger than sodium because it has more electrons. Agree or disagree?

   • Agree: heavier atoms are wider
   • Disagree: more protons pull it smaller
   • Agree: more electrons take up more room
7. 6.

   Noah says silicon is bigger than sodium because it is further along the row. Agree or disagree?

   • Disagree: radius shrinks across
   • Agree: atoms grow as you go across a row
   • Agree: silicon is a metalloid
8. 7.

   Pia says Na⁺ is bigger than a sodium atom because it is charged. Agree or disagree?

   • Agree: ions are bigger than atoms
   • Disagree: it lost its outer shell
   • Agree: charge makes it swell
9. 8.

   Which lists potassium, sodium and magnesium from largest to smallest, Ren?

   • Potassium, sodium, magnesium
   • Magnesium, sodium, potassium
   • Sodium, potassium, magnesium
10. 9.

    Which is larger, chlorine or iodine, Tala?

    • Iodine
    • They are equal
    • Chlorine
11. 10.

    Where on the table are the largest atoms, Zee?

    • Bottom left
    • Top right
    • Top left