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

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

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

   On the map, which element has the highest electronegativity, Luz?

   • Fluorine
   • Lithium
   • Cesium
8. 7.

   What is first ionization energy, Milo?

   • Energy to add a proton
   • Energy to remove one electron
   • Energy to melt a sample of the element
9. 8.

   What units does a Pauling electronegativity have, Pia?

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

    Which of these has the lowest first ionization energy, Ren?

    • Fluorine
    • Cesium
    • Lithium
11. 10.

    Which is more electronegative, carbon or oxygen, Zee?

    • They are equal
    • Oxygen
    • Carbon