Atomic Theory and Structure

Which statement about subatomic of particles is true?

An electron has far less mass and then either a proton or neutron. (d)

According to ___________, all matter was made up of four elements: Earth, fire, and water.

Aristotle (c)

The greek philospher Democritus coined what word for a tiny piece of matter that cannot be divided?

Atom (b)

If element "X" has 107 protons, it's _______ is 107.

Atomic number (a)

To find the number of neutrons in and atom, you would subtract

Atomic number from mass number. (b)

The number of protons in one atom of an element is that element's

Atomic number. (c)

Which of the following is NOT part of John Dalton's atomic theory?

Atoms contain subatomic particles. (c)

In an atomic model that includes a nucleus, positive charge is

Concentrated in the center of an atom. (a)

J.J. Thompson's experiments provided evidence that an atom

Contains negatively charged particles. (b)

Which subatomic particle has a negative charge?

Electron. (a)

Who provided evidence for the existence of a nucleus in an atom?

Ernest Rutherford (d)

Which statement best describes Rutherford's model of the atom?

It is like a huge stadium with a positively charged bumblebee at the center. (d)

In Niels Bohr's model of the atom, electrons move

Like planets orbiting the sun. (b)

The ________Of an isotope is the sum of the number of protons and neutrons and it's nucleus.

Mass number (c)

The nuclei of isotopes of the same element contain different numbers of _______.

Neutrons (b)

The diagram in figure 4-1 (gold foil experiment) shows the results of Rutherford's gold foil experiment. What caused some of the alpha particles to bounce straight back from the gold foil?

Nuclei in the gold atoms (d)

Which statement about subatomic particle's is NOT true?

Protons and neutrons have the same charge. (d)

_________ and _________ have approximately the same mass.

Protons; neutrons (c)

Democritus thought that matter was made of tiny patricles

That could not be divided. (b)

What can you assume has happened is an electron moves to a higher Energy level?

The electron has gained energy. (C)

What does the electron cloud model describe?

The most likely locations of electrons and atoms. (a)

Which of the following is unique for any given element?

The number of protons (c)

According to John Dalton's observations, when elements combine in a compound,

The ratio of their masses is always the same. (a)

Rutherford's gold foil experiment provided evidence for which of the following statements?

There is a dense, positively charged mass in the center of an atom. (d)

Which statement is true about oxygen 17 and oxygen 18?

They are isotopes of oxygen. (c)