GRADE 12 - STEM GEN CHEM

1. What electron configuration matches an oxygen atom?

• 1s²2s²2p⁶3s2, 3p⁶4s²3d¹⁰4p⁵

• 1s²2s²2p⁶

• 1s²2s²2p⁴

• 1s²2s²2p⁶3s²3p⁶4s²3d¹

2. Identify the electron configuration of aluminum (Al)

• 1s² 2s² 2p⁶ 3s² 3p¹

• 1s² 2s² 2p⁶ 3s² 4p¹

• 1s² 2s² 2p⁶ 3s² 3p³

• 1s²2s²2p⁶

3. What atom matches this electron configuration?

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰

• Zinc

• Nickel

• copper

• aluminum

4. What atom matches this electron configuration?

1s²2s²2p⁶3s²

• Aluminum

• Neon

• Magnesium

• Potassium

5. Valence electron located ...

• inside the nucleus

• on the outermost orbit of an atom

• in outer space

• inside proton

6. The correct electronic configuration of Cr (Z=24) is

• [Ar] 3d ⁵ 4s ¹

• [Ar] 3d ⁹ 4s 2

• [Ar] 3d ⁴ 4s 2

• [Ar] 3d ¹⁰ 4s ¹

7. What happens to the atomic numbers as you move from left to right on the periodic table?

• increase

• decrease

• stay the same

• nothing happen

8. Which of the following elements is most likely to have similar properties to those of sodium (Na)?

• Magnesium (Mg)

• Francine (Fr)

• Sulfur (S)

• Titanium (Ti)

9. Which element is located in period 4?

• Zirconium (Zr)

• Beryllium (Be)

• Iron (Fe)

• Silicon (Si)

10. Which element is most likely to have six valence electrons?

• Oxygen (O)

• Barium (Ba)

• Carbon (C)

• Americium(Am)