Chapter 19: Properties of Atoms and Periodic Table

Quarks

Quarks

________: smaller particles that make up protons and neutrons.

Metals

________ are located to the left of the metalloids.

Nonmetals

________ are located to the right of the metalloids.

tremendous speeds

To study quarks, scientists accelerate charged particles to ________ and then force them to collide with- or smash into- protons.

Cloud

A(n) ________ of negatively charged electrons surrounds the nucleus of the atom.

Proton

The ________ has a positive charge and the neutron has no charge.

Neutrons

________: neutral particles that do not have an electrical charge.

Bubble Chambers

________ can be used by scientists to study the tracks left by subatomic particles.

Electrons

________: particles with an electrical charge of 1-

Mendeleev

________ discovered that the elements have a periodic pattern in their chemical properties.

Horizontal Rows of Elements

Periods: The ________ on the periodic table.

Scientists

________ hypothesize that electrons are not composed of smaller particles and are one of the most basic types of particles.

Periodic Table

________: the elements are arranged by increasing atomic number and by changes in physical and chemical properties.

Elements

________ have been named in a variety of ways.

strong nuclear force

Scientists theorize that an arrangement of three quarks held together with the ________ produces a proton.

Atoms

________ are composed of particles called protons, neutrons, and electrons.

Isotopes

________: Atoms of the same element that have different numbers of neutrons.

Electron Cloud

________: the area around the nucleus of an atom where its electrons are most likely found.

Energy Levels

All halogens have seven electrons in their outer ________.

Atom

the smallest piece of matter that still retains the property of the element

Nucleus

a small, positively-charged center of the atom

Protons

particles with an electrical charge of 1+

Neutrons

neutral particles that do not have an electrical charge

Electrons

particles with an electrical charge of 1-

Electron Cloud

the area around the nucleus of an atom where its electrons are most likely found

Atomic Number

The number of protons in an atom is equal to a number

Mass Number

the sum of the number of protons and the number of neutrons in the nucleus of the atom.'

Isotopes

Atoms of the same element that have different numbers of neutrons

Average Atomic Mass

the weighted-average mass of the mixture of its isotopes

Periodic Table

the elements are arranged by increasing atomic number and by changes in physical and chemical properties

groups

families

Electron Dot Diagram

uses the symbol of the element and dots to represent the electrons in the outer energy level

Periods

The horizontal rows of elements on the periodic table