Atomic Number , Mass Number and Isotopes

• Y , X , Z

• Z , X , Y

• X , Z , Y

• Y , Z , X

Which of the following is not a part of Dalton’s atomic theory?

• Atoms are always in motion

• All elements are composed of atoms

• Atoms of the same element are alike

• Atoms that combine do so in

  simple whole-number ratios

According to the Rutherford’s experiment, ___________ move through __________ surrounding the nucleus.

• electrons positive charges

• electrons. empty space

• protons. empty space

• neutrons. negative charges

The number 80 in the name bromine-80 represents _____________.

• none of the above

• the sum of protons and electrons

• the atomic number

• the mass number

Tags

NGSS.HS-PS1-8

How do the isotopes hydrogen-2 and hydrogen-3 differ?

• Hydrogen-3 has two neutrons

• Hydrogen-2 has three protons

• Hydrogen-2 has no protons

• Hydrogen-3 has one more electron than hydrogen-2

Tags

NGSS.HS-PS1-8

Isotopes of the same element have __________

• the same number of neutrons but different numbers of electrons

• The same number of protons but different number of neutrons .

• the same number of protons but

  different numbers of electrons

• the same number of neutrons but different numbers of protons

Which of the following atoms are isotopes of each another?

• Q and R

• P and Q

• P and S

• P and R

Tags

NGSS.MS-PS1-1

The above atom has an atomic number of _______ and mass number of __________.

• 18. 9

• 8. 18

• 17. 8

• 9. 17

Tags

NGSS.MS-PS1-1

Three isotopes of oxygen occur in nature: oxygen-16, oxygen-17, and oxygen-18. If the atomic mass of oxygen is 15.9994, which of the three isotopes, if any, is the most abundant?

• Oxygen-18

• Oxygen-16

• Oxygen-17

• All are equally abundant

• a.16 b.16 c.23 c.23 e.B f.5 g.5

• a.23 b.16 c.23 d.16 e.B f.6 g.2

• a.26 b.16 c.23 c.20 e.B f.9 g.5

• a.17 b.17 c.24 c.24 e.A f.6 g.6

• a.16 b.16 c.23 c.23 e.P f.5 g.5

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2