The Structure of Atoms

Every atom has a(n) ________charged nucleus surrounded by a(n) ____ charged electron cloud; however, atoms can have different numbers of ________, neutrons, and electrons.

positively; negatively; protons

A positively charged particle in the nucleus of an atom is called a(n)

proton.

All atoms of the same element have the same number of__________________

protons

Ions have same number of_____ and are the same element they were before gaining or losing electrons.

protons

positively charged particle in the nucleus of an atom

protons

A neutral atom has the same number of _____________in its nucleus as___________in its electron cloud.

protons; electrons

All the substances around you, including your body and the air you breathe are made up of millions and millions of___

atoms

Every kind of element is made up of its own kind of

atoms.

The properties of an element and the ways its _____combine are determined mainly by the number and the arrangement of the_____________in its atoms.

atoms; particles

An atom that has a charge because it has gained or lost electrons is called a(n)________________

ion

an atom that has a charge because it has gained or lost electrons

ion

one or more atoms of an element having the same number of protons but a different number of neutrons

isotope

One of two or more atoms of an element having the same number of protons but a different number of neutrons is called a(n) ____________________

isotope.

uncharged particle in the nucleus of an atom

neutron

An uncharged particle in the nucleus of an atom is called a(n)

neutron.

region at the center of an atom that contains most of the mass of an atom

nucleus

The electrons closest to the___have the least energy; the electrons farthest from the ___ have the most energy.

nucleus; nucleus

If you could enlarge an atom to be 1 million times larger than its natural size, it would be the size of a(n) ______; this object enlarged to the same degree would be the size of

orange; Earth.

Atoms are composed of several basic types of very small ; the of each of these particles gives different kinds of atoms their unique identity

particles; number

_____ are much smaller in size than ______ and neutrons, and they move very quickly.

Electrons; protons

The region at the center of an atom that contains most of the mass of the atom is called the

Nucleus

the number of protons in the nucleus of an atom of an element

atomic number

The number of protons in the nucleus of an atom of an element is called the ________ a. Each _____ has a different atomic number. b. The number of _____ in the nucleus of the atom determines the identity of the atom.

atomic number. a. element. b. protons

negatively charged particle that occupies the space in an atom outside the nucleus

electron

The region surrounding an atom's nucleus where one or more electrons are most likely to be found is called a(n)

electron cloud

region surrounding an atom's nucleus where one or more electrons are often found

electron-cloud

A negatively charged particle that occupies the space in an atom outside the nucleus is called a(n)

electron.

A neutral atom can gain one or more ___________giving the atom a(n) ______charge; a neutral atom can lose one or more_______giving the atom a(n) ___________charge.

electrons; negative; electrons; positive charge.

For each element, the number of_____and the number of_____ can vary.

electrons; neutrons

An electron cloud is mostly made up of _________space; it is not a cloud of

empty: charge.