Comparing Isotopes

What defines an element uniquely?

• Number of neutrons

• Mass number

• Number of protons

• Number of electrons

In a neutral atom, how do the numbers of protons and electrons compare?

• Equal numbers of protons and electrons

• More electrons than protons

• More protons than electrons

• The relationship varies

Tags

NGSS.MS-PS1-1

What does the mass number of an atom represent?

• Number of electrons only

• Sum of protons and neutrons

• Number of protons only

• Sum of protons and electrons

Tags

NGSS.MS-PS1-1

How can you determine the number of neutrons in an atom?

• Add the number of electrons to the atomic number

• Subtract the number of electrons from the atomic number

• Subtract the atomic number from the mass number

• Add the atomic number to the mass number

What is an isotope?

• Atoms with different numbers of protons

• Atoms with different numbers of electrons

• Atoms of the same element with different numbers of neutrons

• Atoms of different elements with the same number of neutrons

Tags

NGSS.MS-PS1-1

Which of the following is true about carbon-14?

• It has 14 protons

• It has 8 neutrons

• It has 14 electrons

• It has 6 electrons

Tags

NGSS.MS-PS1-1

What is an ion?

• A group of atoms with the same number of protons

• An atom or group of atoms with a positive or negative charge

• An atom or group of atoms with a neutral charge

• An atom with equal numbers of protons and electrons

Tags

NGSS.MS-PS1-1

How is an anion formed?

• By gaining a proton

• By gaining an electron

• By losing an electron

• By losing a proton

What helps to remember that anions are negatively charged?

• The word 'anion' starts with 'a', which stands for 'atom'

• The word 'anion' sounds like 'negative'

• The letter 't' in 'anion' looks like a plus sign

• The letter 'n' appears twice in 'anion'

What charge does a cation carry?

• Neutral

• Variable

• Positive

• Negative