Understanding Atomic Numbers in Elements

This video tutorial explains how to find the atomic number of elements on the periodic table. The atomic number is the number above the element symbol and represents the number of protons in an atom. It is unique to each element and also indicates the number of electrons in neutral atoms. The video provides examples of atomic numbers for elements like hydrogen, helium, sodium, oxygen, iron, copper, carbon, and argon. The atomic number increases by one as you move across a period on the periodic table. The tutorial concludes with a reminder of the importance of the atomic number in identifying elements.

What is the atomic number of helium?

• 1

• 2

• 4

• 3

Which element has an atomic number of 11?

• Sodium

• Carbon

• Iron

• Helium

What does the atomic number of an element represent?

• Number of electrons

• Number of protons

• Number of neutrons

• Number of atoms

For a neutral atom, what does the atomic number also indicate?

• Number of molecules

• Number of isotopes

• Number of electrons

• Number of neutrons

What is the atomic number of oxygen?

• 9

• 6

• 7

• 8

How many protons are in an atom of iron?

• 26

• 24

• 27

• 25

What is the atomic number of copper?

• 28

• 30

• 27

• 29

Which element has an atomic number of 6?

• Nitrogen

• Helium

• Oxygen

• Carbon

What is the atomic number of argon?

• 19

• 16

• 17

• 18

As you move across a period on the periodic table, how does the atomic number change?

• Decreases by 1

• Increases by 1

• Remains the same

• Doubles