Atomic Number and Isotopes of Hydrogen

The video tutorial explains how to identify elements based on the number of protons, which corresponds to the atomic number on the periodic table. It highlights that hydrogen, with one proton, is atomic number one. The tutorial also discusses isotopes, specifically hydrogen-2, which has one proton and one neutron, emphasizing that the identity of an element is determined by its protons, not neutrons.

What does the atomic number of an element represent?

• The number of neutrons in the element

• The total mass of the element

• The number of protons in the element

• The number of electrons in the element

Where can you find the atomic number of an element on the periodic table?

• To the left of the element symbol

• Below the element symbol

• To the right of the element symbol

• Above the element symbol

Which element is identified by having one proton?

• Carbon

• Hydrogen

• Oxygen

• Helium

What is the atomic number of hydrogen?

• 0

• 3

• 2

• 1

What is an isotope of hydrogen with one proton and one neutron called?

• Hydrogen-1

• Deuterium

• Hydrogen-2

• Helium

Why is hydrogen-2 still considered hydrogen?

• Because it has no neutrons

• Because it has two protons

• Because it has one proton

• Because it has two neutrons