Question

1. give the symbol and number of protons in one atom of: lithium ____________ bromine __________ iron __________ copper __________ oxygen __________ mercury __________ krypton __________ helium __________ 8. give the symbol and number of electrons in a neutral atom of: uranium __________ chlorine __________ boron __________ iodine __________ antimony __________ xenin ____________

Explanation:

Step1: Recall periodic - table properties

The atomic number of an element is equal to the number of protons in an atom. In a neutral atom, the number of electrons is equal to the number of protons. We use the periodic table to find the symbol and atomic number of each element.

Step2: Lithium

Symbol: Li, Number of protons = 3

Step3: Iron

Symbol: Fe, Number of protons = 26

Step4: Oxygen

Symbol: O, Number of protons = 8

Step5: Krypton

Symbol: Kr, Number of protons = 36

Step6: Bromine

Symbol: Br, Number of protons = 35

Step7: Copper

Symbol: Cu, Number of protons = 29

Step8: Mercury

Symbol: Hg, Number of protons = 80

Step9: Helium

Symbol: He, Number of protons = 2

Step10: Uranium

Symbol: U, Number of protons (and electrons in neutral atom) = 92

Step11: Boron

Symbol: B, Number of protons (and electrons in neutral atom) = 5

Step12: Antimony

Symbol: Sb, Number of protons (and electrons in neutral atom) = 51

Step13: Chlorine

Symbol: Cl, Number of protons (and electrons in neutral atom) = 17

Step14: Iodine

Symbol: I, Number of protons (and electrons in neutral atom) = 53

Step15: Xenon (assuming you mean Xenon instead of Xenin)

Symbol: Xe, Number of protons (and electrons in neutral atom) = 54

Answer:

Lithium: Li, 3
Iron: Fe, 26
Oxygen: O, 8
Krypton: Kr, 36
Bromine: Br, 35
Copper: Cu, 29
Mercury: Hg, 80
Helium: He, 2
Uranium: U, 92
Boron: B, 5
Antimony: Sb, 51
Chlorine: Cl, 17
Iodine: I, 53
Xenon: Xe, 54