Atomic Structure

An atom has 30 protons, 30 electrons, and 34 neutrons. What element is this atom?

• Selenium
• Erbium
• Zinc
• Beryllium

An atom has 17 protons, 17 electrons, and 18 neutrons. What is the mass number of this atom?

• 35

• 34

• 17

• 18

An phosphorous ion has 15 protons, 18 electrons, and 16 neutrons. What is the charge on this ion?

• +1
• -1
• +3
• -3

A sodium ion has a charge of +1. How many protons and electrons does this ion have?

• 11 protons and 11 electrons
• 11 protons and 10 electrons
• 11 protons and 12 electrons
• 12 protons and 11 electrons

An atom has 28 protons, 28 electrons, and 31 neutrons. What is the mass number of this atom?

• 28
• 59
• 31
• 3

An atom has a mass number of 55 and an atomic number of 26. How many neutrons are in this atom?

• 55
• 29
• 26
• 52

An atom has a mass number of 31, and has 16 neutrons. What is the atomic number of this atom?

• 16
• 31
• 15
• 30

An ion has 27 protons, 25 electrons, and 32 neutrons. What is the symbol for this ion?

• Co⁺²

• Co^-2

• Co⁺⁵

• Co

An atom has an atomic number of 19 and a mass number of 40. How many protons and neutrons are in this atom?

• 19 protons, 40 neutrons
• 40 protons, 19 neutrons
• 21 protons, 19 neutrons
• 19 protons, 21 neutrons

An atom has an atomic number of 16 and a mass number of 32. How many electrons are in this atom?

• 16

• 32

• 18

• None of the above