Atomic structure, ions, isotopes

The mass number of an element that has18 protons, 18 electrons, and 19 neutrons is _____.

• 12.5
• 13
• 25
• 37

The atomic number of an element that has 9 protons, 9 electrons, and 10 neutrons is _____.

• 9
• 10
• 19
• 28

Tags

NGSS.MS-PS1-1

If the number of electrons in an atom changes you make a(n) __________________.

• ion
• isotope
• new element
• isomer

Carbon-12 has 98.2% abundance, carbon-13 has 1.7% abundance, and carbon-14 has 0.1% abundance.  Which isotope contributes most to the average atomic mass?

• Carbon-12
• Carbon-13
• Carbon-14
• They all contribute equally

How many neutrons does uranium-239 have

• 92
• 147
• 239
• 331

Tags

NGSS.HS-PS1-8

Which particle contributes least to the total mass of an  atom?

• Proton
• Neutron
• Electron
• Nucleus

Atomic Number:  26
Neutrons:  30
Electrons:  25

• Normal Atom
• Isotope
• Anion
• Cation

Which statement about subatomic particles is true?

• Protons, neutrons, and electrons all have about the same mass.
• Unlike protons or neutrons, electrons have no mass.
• Neutrons have no charge and no mass.
• An electron has far less mass than either a proton or neutron.

Which of the following is unique for any given element?

• the number of neutrons
• the charge on the electrons
• the number of protons
• the mass of a neutron

Which statement is true about oxygen-17 and oxygen-18?

• They do not have the same number of protons.
• Their atoms have an identical mass.
• They are isotopes of oxygen.
• The have the same mass number.

Tags

NGSS.MS-PS1-1