to put electricity into an electrical device such as a battery
My phone went dead during a very important conversation because the battery was not charged.
column
a vertical row or list
The elements on a periodic chart that are in the same column have the same number of electrons.
electrons
an extremely small piece of matter with a negative electrical charge
An element has the same number of protons as electrons.
elements
an element is a substance that is made entirely from one type of atom
As of 2006, scientist know of 117 elements.
horizontally
parallel to the ground
As part of his physical therapy, he was required to lie horizontally for 20 hours a day.
intervals
a period between two events or times, or the space between two points
Most dentists recommend that you get your teeth cleaned at regular intervals--usually every six months.
isotopes
a form of an atom which has a different atomic weight from other forms of the same atom but the same chemical structure
An isotope of hydrogen called deuterium has one neutron.
negatively
having a negative charge
The negatively charged particle of an element is called the electron.
neutrons
a part of an atom that has no electrical charge
You can figure out the number of neutrons by subtracting the atomic number from the mass number.
noble
chemically noncreative
There are six noble gases on the periodic table; they rarely react with other elements.
nucleus
the central part of an atom
The nucleus of an atom is usually made up of protons and neutrons.
particles
one of the most simple parts of all matter, such as an electron, a proton or a neutron
The atom is the smallest indivisible particle of matter.
periodic table
an arrangement of the chemical elements according to their atomic numbers, to exhibit the periodic law
Every student that studies chemistry has to become familiar with the periodic table.
positively
having a positive charge
The positively charged particle of an element is called the proton.
properties
an essential or distinctive attribute or quality of a thing
Many scientists attempted to study the properties of his mind; they were curious to know what made him so intelligent.
protons
a type of elementary particle which has a positive electrical charge and is found in the nucleus of all atoms
The number of protons in an atom determines the atomic number of a chemical element.
respectively
in regard to each of two or more
The first and second prizes went to Tom and Jerry, respectively.
revolve
to move or cause something to move round a central point or line
The Earth revolves around the sun.
shell
a group of nucleons of approximately the same energy
A shell can be any seven energy levels on which an electron may exist within an atom.
vertical
straight up or down
The vertical blinds made the house look bigger.
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