Science Chapter 4

If an atom of an element has a mass number of 31 and 16 neutrons in its nucleus, what is the atomic number of the element?

31 - 16 = 15

A certain atom has 26 protons, 26 electrons, and 30 neutrons. Its mass number is

56

If an atom of germanium has a mass number of 70 and an atomic number of 32, how many neutrons are in its nucleus?

70 - 32 = 38

A sample of calcium contains calcium-40, calcium-44, calcium-42, calcium-48, calcium-43, and calcium-46 atoms. Explain why these atoms can have different mass numbers, but they must have the same atomic number.

All the atoms of an element have the same number of protons.

According to ______ all matter was made up of four elements- earth, air, fire, and water

Aristotle

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

Atom

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

Atomic Number

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

Atomic number from mass number

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

Atoms contain subatomic particles

J.J. Thomson's experiment provided evidence that an atom

Contains negatively charged particles.

What specific word comes from a Greek word meaning "uncut"? Which Greek philosopher first used the word to describe matter?

Democritus - Proposed the word atomos.

A particle that moves around the nucleus is an

Electron

The _____ in an atom has a negative charge

Electron

Which subatomic particle has a negative charge?

Electron

Each inner energy level of an atom has a maximum number of ______ it can hold.

Electrons

Compare the masses of neutrons, protons, and electrons.

Electrons have an extremely small mass, compared to either protons and neutrons.

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

Ernest Rutherford

The maximum number of electrons in the second energy level of an atom is 4.

False: Eight

The region around the nucleus occupied by the electrons is called the negative zone.

False: Electron Cloud

The mass of an (electron) is about equal to the mass of a proton.

False: Neutron

The central core of an atom is called the hub.

False: Nucleus

Two isotopes of carbon are carbon-12 and carbon-14. These isotopes differ from one another by two protons.

False: neutrons

Atoms of the same element with different numbers of neutrons are called

Isotopes

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

Like planets orbiting the sun.

Protons and _______ are found in the nucleus of an atom

Neutrons

The center of the atom where protons and neutrons are located is the

Nucleus

If element Q has 11 protons, its atomic ______ is 11.

Number

Which statement about subatomic particles is true?

Protons, neutrons, and electrons all have about the same mass.

Particles of matter that make up protons and neutrons are

Quarks

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

They are isotopes of oxygen

According to present atomic theory, the location of an (electron) in an atom cannot be pinpointed exactly.

True

So far, scientists have conformed the existence of (six) different quarks.

True

The sum of the number of protons and neutrons in an atom is the mass number.

True

Which of the following most accurately represents John Dalton's model of the atom?

a tiny, solid sphere with a predictable mass for a given element

In Bohr's model of the atom, ______ move in fixed orbits around the nucleus

electrons

John Dalton concluded that all the atoms of a single _______ have the same mass

element

The subatomic particle that J.J. Thomson discovered has a _____ charge

negative

The nuclei of isotopes contain different numbers of

neutrons

The region in which an electron is most likely to be found is called an

orbital

Horizontal rows of the periodic table is called

periods