The number on the top left is

• the number of electrons and protons

• the number of protons and neutrons

• the number of electrons and neutrons

What is the approximate mass of an atom that contains 26 protons, 26 electrons and 19 neutrons?

• 26 amu

• 45 amu

• 52 amu

• 71 amu

Which two notations represent isotopes of the same element?

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• 

Tags

NGSS.HS-PS1-8

Which numerical setup can be used to determine the atomic mass of lithium?

• (7.5)(6.02 amu) + (92.5)(7.02 amu)

• (0.925)(6.02 amu) + (0.075)(7.02 amu)

• (0.075)(6.02 amu) + (0.925)(7.02 amu)

• (92.5)(6.02 amu) + (7.5)(7.02 amu)

Tags

NGSS.HS-PS1-7

Two atoms that are different isotopes of the same element have

• the same number of protons and same number of neutrons

• the same number of protons but a different number of neutrons

• a different number of protons but the same number of neutrons

• a different number of protons and a different number of neutrons

the mass of an electron is

• equal to the mass of a proton

• equal to the mass of a neutron

• greater than the mass of a proton

• less than the mass of a neutron

Which notations represent atoms that have the same number of protons but a different number of neutrons?

• H-2 and He-3

• S-32 and S-32

• Cl-35 and Cl-37

• Ga-70 and Ge-73

Atoms are neutral because the number of

• protons equals the number of neutrons

• protons equals the numbers of electrons

• neutrons is greater than the number of protons

• neutrons is greater than the number of electrons

Tags

NGSS.HS-PS1-7

What is the total number of neutrons in K-42

• 19

• 20

• 23

• 42

Tags

NGSS.HS-PS1-8

Which notations represent hydrogen isotopes?

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• 
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•