The video tutorial explains how the type of element is defined by the number of protons in an atom's nucleus, known as the atomic number. It introduces isotopes, which are different versions of the same element with varying numbers of neutrons. The tutorial uses chlorine as an example, detailing its two stable isotopes, chlorine-35 and chlorine-37, and explains how to calculate the average atomic mass based on their natural abundance. It also discusses the concept of mass defect, where the combined mass of protons and neutrons in a nucleus is slightly less than their individual masses.

What defines the type of element an atom is?

• Number of neutrons

• Number of electrons

• Number of protons

• Number of isotopes

Which element has exactly six protons in its nucleus?

• Hydrogen

• Carbon

• Oxygen

• Chlorine

Tags

NGSS.MS-PS1-1

What are isotopes?

• Elements with the same number of protons but different numbers of neutrons

• Elements with the same number of neutrons but different numbers of protons

• Elements with the same number of electrons but different numbers of protons

• Elements with different numbers of protons and neutrons

How many neutrons does chlorine-35 have?

• 20

• 19

• 18

• 17

How many protons are in chlorine-37?

• 20

• 17

• 18

• 19

What percentage of chlorine found in nature is chlorine-35?

• 100%

• 75.77%

• 50%

• 24.23%

What is the average atomic mass of chlorine?

• 35.00

• 35.45

• 36.00

• 37.00

What is the term for the difference between the combined mass of protons and neutrons and their individual masses?

• Atomic mass

• Neutron deficit

• Mass defect

• Isotope difference

Why is the atomic mass of chlorine-35 slightly less than 35 unified atomic mass units?

• Because of the number of protons

• Because of the mass of electrons

• Due to the number of neutrons

• Due to the mass defect

Where can you find the exact atomic mass of chlorine-35?

• In a physics textbook

• In atomic mass tables

• In a chemistry textbook

• In the periodic table