# data[].attributes.body
Two or more atoms bound together as a single unit and forming part of a molecule.

A lot of atoms started with groups of atoms.

# data[].attributes.body
A period in the periodic table is a row of chemical elements.

There are many periods on the periodic table.

# data[].attributes.body
A row of arranged collums of the elements according to atomic number based on the periodic law.

On the periodic table there are 118 elements.

# data[].attributes.body
Mass of an atom of a chemical expressed in atomic mass units.

Atomic mass is the mass of an atom.

# data[].attributes.body
Unit of mass for expressing masses of atoms or molecules.

The dalton or unified atomic mass unit is a unit of mass widely used in physics and chemistry

# data[].attributes.body
One or two more atoms with the same atomic number but have different amount of nuetrons.

Carbon has three isotopes.

# data[].attributes.body
The sum of the number of nuetrons and protons in an atomic nucleus.

The mass number is also called the atomic number.

# data[].attributes.body
the order of an element in Mendeleyev's table of the elements; equal to the number of protons in the nucleus or electrons in the neutral state of an atom of an element.

The atomic number is the amount of protons an object on the periodic table and is in the lefthand corner.

# data[].attributes.body
A part of the cell containing DNA and RNA responsible for growth.

Ernest Rutherford was the person who discovered the nucleus.

# data[].attributes.body
Make up the nucleus of an atom, and has no charge.

James Chadwick discovered that neutrons in the nucleus.

# data[].attributes.body
Make up nucleus of an atom and have a positive charge.

Ernest Rutherford names the particles in the nucleus protons.

# data[].attributes.body
A beam of electrons emitted by the cathode of an electrical discharge tube.

In 1876 Eugen Goldstein named the cathode ray.

# data[].attributes.body
Smallest particle that make up an atom. Carry a negative charge, and make up part of an atom's nucleus.

J.J. Thompson discovered electrons.

# data[].attributes.attachment_link.title
American Welding Society (AWS) - Your Source for Welding Expertise

# data[].attributes.attachment_link.description
Learn more about the benefits of AWS education and explore our course catalog to help you achieve your career goals.

# data[].attributes.body
A theory of a structure of an atom.

John Dalton originally came up with the atomic theory.

# data[].attributes.body
Basic unit of an element.

Atoms are the smallest unit  unit of ordinary matter.