What makes an atom neutral?

• Equal number of protons and neutrons

• Equal number of protons and electrons

• More protons than electrons

• More electrons than protons

What are the negatively charged particles in an atom called?

• Ions

• Protons

• Electrons

• Neutrons

How does an atom become a positively charged ion?

• By losing electrons

• By losing protons

• By gaining protons

• By gaining electrons

What happens to the element if the number of protons in an atom changes?

• It remains the same element

• It becomes an isotope

• It becomes a different element

• It becomes an ion

What defines an isotope of an element?

• Different number of ions

• Different number of neutrons

• Different number of electrons

• Different number of protons

Which of the following is an example of an isotope?

• Hydrogen-1 and Hydrogen-2

• Oxygen-16 and Oxygen-18

• All of the above

• Carbon-12 and Carbon-13

What does the number after an element's name (e.g., Carbon-14) represent?

• Atomic number

• Number of protons

• Number of electrons

• Mass number

Tags

NGSS.HS-PS1-8

Why do atomic masses have decimals?

• Because of the average mass of all isotopes

• Because of the mass of protons

• Because of the mass of neutrons

• Because of the mass of electrons

How is the average atomic mass of an element calculated?

• By taking the mass of the most common isotope

• By averaging the masses of all isotopes based on their abundance

• By adding the number of protons and neutrons

• By adding the masses of all isotopes

Which isotope of carbon is the most abundant in nature?

• Carbon-13

• All are equally abundant

• Carbon-14

• Carbon-12