Chapter 1 Atoms

Review

Uncharged particle in the nucleus of an atom

• neutron

The number of neutrons plus protons in the nucleus of an atom

• Mass number

The number of protons in the nucleus

• Atomic number

Matter that is made up of only one kind of atom

• element

A pure substance whose smallest unit is made of atoms of more than one

element• element

Region surrounding the nucleus in which the electrons move about

• Electron cloud

A negative charge particle that is part of every kind of matter

• electron

A sample of matter with the same composition and properties

throughout• substance

Atoms of the same element that have different number of neutrons

• isotopes

Elements that make up about 97% of the human body

• nonmetals

Elements that generally have a shiny or metallic luster

• metals

A positively charged particle in the nucleus

• proton

Two or more substances that are together, but not combined

• mixture

The mass of the mixture of the isotopes for an element

• Atomic mass

Elements that have characteristics of both metals and nonmetals

• metalloids

Atom, elements, atomic number, metals

Fill in the blank with the words from above.• Most elements are .___.• The periodic table lists ___.• An element is made up of only one kind of __.• Isotopes can have the same ___.

• Metals• Elements• Atom• Atomic number

Where are metalloids found on the periodic table?

• Between the metals

What led scientists to believe that the atom could be broken down into

smaller particles• Cathode rays

Elements in a ___ are always combined in the same proportion by

mass• compound

What did the Greeks name what they believed to be the tiniest part of

matter?• atom

An example of a homogenous mixture

• Air• H2O

Atoms of the same element always have the same number ___

• protons

How is an electron cloud shaped?

• sphere

What is the chemical compound for ammonia? (three Hydrogen and one

Nitrogen)• NH3

JJ Thomson discovered that ___ charges attract each other in his

cathode-ray tube experiment• opposite

___ contains only one kind of atom

• Elements

Isotopes are atoms of the same element that have a different number

of ___• neutrons

Particles in an atom’s nucleus that do not have an electric charge are called

___?• neutrons

Which is not an example of matter

• Dust particle• Air• A beam of light

Beam of light

The mass number of an atom consists of the mass of ___.

• Protons and neutrons

What does the atomic number of an element tell?

• Number of protons

How do you find the number of neutrons in an isotope?

• The atomic number from the mass number

An atom of the element with atomic number of 6 always has ___ in its

nucleus• Six protons

Rutherfod’s experiment showed that most of an atom is made of mostly___.• space

Who developed a model called the atomic theory of matter?

• John Dalton

Most of the elements found on the left side of the periodic table are___.

• metals

During Thompson’s experiments, what was affected by a magnet?

• electrons

Which of the following is NOT associated with metals?

• Electric conductivity• Brittleness• shininess

• brittleness

Water is an example of what kind of substance?

• compound

Air is an example of what kind of substance?

• Homogeneous mixture

What is matter that is NOT considered to be a single substance?

• mixture

Be able to identify all the parts of an atom and label each part

• Electron• Electron cloud• Neutron• Nucleus• Proton

Know the components of an element

• Number of protons = number of electrons• Atomic number = number of protons• Mass number = number of protons + number

of neutrons