Ionization energy, electronegativity and reactivity trends

Answer Key - Grade 10 Science Worksheet - Building Confidence

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

1. 1.

   Lithium's first ionization energy is 5.392 eV and sodium's is 5.139 eV (PubChem). How much lower is sodium's, to 0.01 eV, Ari?

   0.25 eV
2. 2.

   Sodium's first ionization energy is 5.139 eV and potassium's is 4.341 eV (PubChem). How much lower is potassium's, to 0.01 eV, Bo?

   0.8 eV
3. 3.

   Potassium's first ionization energy is 4.341 eV and cesium's is 3.894 eV (PubChem). How much lower is cesium's, to 0.01 eV, Esme?

   0.45 eV

4. Read this first

   increases

   First ionization energy and electronegativity both increase across a period, left to right, and up a group. Fluorine has the highest electronegativity, 3.98 on the Pauling scale.

5. 4.

   On the map, what happens to ionization energy going down a group, Jun?

   • It stays the same
   • It rises
   • It falls
6. 5.

   On the map, what happens to electronegativity across a period, Kira?

   • It falls
   • It rises
   • It stays the same
7. 6.

   What is first ionization energy, Milo?

   • Energy to add a proton
   • Energy to remove one electron
   • Energy to melt a sample of the element
8. 7.

   What does electronegativity describe, Noah?

   • Pull on shared electrons
   • Speed of electrons
   • The number of neutrons inside
9. 8.

   What units does a Pauling electronegativity have, Pia?

   • Joules, like other energies
   • No units: a scale number
   • Grams
10. 9.

    Which element is the most electronegative, Tala?

    • Chlorine
    • Oxygen
    • Fluorine
11. 10.

    Which is more electronegative, carbon or oxygen, Zee?

    • Oxygen
    • They are equal
    • Carbon