Which of the following parts of John Dalton's atomic theory are incorrect?

• matter is composed of atoms

• atoms are indivisible

• atoms of one element differ from atoms of another

• atoms combine to form compounds

Tags

NGSS.HS-PS1-7

This Greek philosopher lead to John Dalton's theory on atoms.

• Aristotle

• Socrates

• Plato

• Democritus

What did Rutherford use in his gold foil experiments to develop his theory?

• positive alpha particles and electrons

• alpha particles negative charge

• gold foil's negative charge and beta particles

• gamma particles

The atomic mass is determined by taking the ...

• average of all of the isotopes, stable and unstable.

• totaling up the isotopes mass numbers.

• weighted average of the masses of all naturally-occurring isotopes.

• average of the atomic numbers of the isotopes.

The atomic number is the number of ___.

• electrons

• protons

• neutrons

• nuclear mass

What is the name for the emission of rays and particles by a radioactive material?

• gamma rays

• nuclear decay

• half life

• radiation

Tags

NGSS.HS-PS1-8

What is the charge of a gamma ray?

• positive

• negative

• no charge

Tags

NGSS.HS-PS4-3

What determines the stability of an atom?

• ratio of protons to neutrons.

• ratio of protons to electrons.

• ratio of neutrons to electrons.

What is the charge of an alpha particle?

• positive two

• negative

• neutral

Calculate the atomic mass of gallium (Ga). Gallium has two isotopes: ⁶⁹Ga and ⁷¹Ga. Gallium-69 has a relative abundance of 60.12 %. Gallium-71 has a relative abundance of 39.88 %. 

• 70.01

• 69.7976

• 70.82

• 69.245

Tags

NGSS.HS-PS1-8