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?

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

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

   • It has more electrons
   • It has fewer shells
   • It has more protons
7. 6.

   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
8. 7.

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

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

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

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

    Which is larger, chlorine or iodine, Tala?

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

    Where on the table are the largest atoms, Zee?

    • Top right
    • Bottom left
    • Top left