Chapter 19: Properties of Atoms and Periodic Table 

________: smaller particles that make up protons and neutrons.

________ are located to the left of the metalloids.

________ are located to the right of the metalloids.

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

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

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

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

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

________: particles with an electrical charge of 1-

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

Periods: The ________ on the periodic table.

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

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

________ have been named in a variety of ways.

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

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

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

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

All halogens have seven electrons in their outer ________.

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

a small, positively-charged center of the atom

particles with an electrical charge of 1+

neutral particles that do not have an electrical charge

particles with an electrical charge of 1-

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

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

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

Atoms of the same element that have different numbers of neutrons

the weighted-average mass of the mixture of its isotopes

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

families

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

The horizontal rows of elements on the periodic table