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.

   Lithium's radius is 145 pm and sodium's is 180 pm (Slater). By what percent does radius grow from lithium to sodium, to 0.01%, Ari?

   24.14 %
2. 2.

   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 %
3. 3.

   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 %

4. 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

5. 4.

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

   • They lose shells each step
   • They each have fewer electrons, step by step
   • More protons pull the same 10 electrons
6. 5.

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

   • Mg²⁺
   • Na⁺
   • O²⁻
7. 6.

   Using the table, K⁺ and Cl⁻ both have 18 electrons. Why is K⁺ smaller, Luz?

   • It has fewer shells
   • It has more protons
   • It has more electrons
8. 7.

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

   • Agree: atoms grow as you go across a row
   • Agree: silicon is a metalloid
   • Disagree: radius shrinks across
9. 8.

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

   • Agree: charge makes it swell
   • Agree: ions are bigger than atoms
   • Disagree: it lost its outer shell
10. 9.

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

    • Potassium, sodium, magnesium
    • Magnesium, sodium, potassium
    • Sodium, potassium, magnesium
11. 10.

    Where on the table are the largest atoms, Zee?

    • Top left
    • Bottom left
    • Top right