Fireworks that contain metallic salts such as sodium, strontium, and barium can generate bright colors. a technician investigates what colors are produced by the metallic salts by performing flame tests. during a flame test, a metallic salt is heated in the flame of a gas burner. each metallic salt emits a characteristic colored light in the flame. 72 explain why the electron configuration of 2-7-1-1 represents a sodium atom in an excited state. [1]

Answer is: The electrons moved from the second energy level to the fourth.

Atomic number (Z) of sodium is 11, it means that it has 11 protons and 11 electrons, so atom of sodium is neutral.

Electron configuration of sodium atom in a ground state:

₁₁Na 1s² 2s² 2p⁶ 3s¹ or 2-8-1-0.

In a ground state of sodium atom, fourth energy level is empty.

In a excited state electron from second energy level (2s² 2p⁶) moves to fourth energy level.

thats how its supposed to be

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.