ATOMIC STRUCTURE
definition of an atom
An element's atomic number represents this
What is the number of PROTONS
In the periodic table, elements are put into these two main groups
What are metals and nonmetals
how many known elements are there in total
118
When an atom loses or gains electrons, it becomes this
What is an ION
Most of an atom is this
What is empty space
Horizontal rows (<---->) on the periodic table are called this
What are periods
The most reactive group of metals are these.
What are the alkali metals (Group 1)
The first element is this (atomic number 1)
hydrogen
When the number of neutrons is not the same as the number of protons, you have this
What is an ISOTOPE
The three main subatomic particles that atoms are made of
What are protons, neutrons, and electrons
Vertical (up-and-down) columns on the periodic table are called this
What are groups (or families)
Non-metallic elements, such as arsenic, that have some properties of metals are known as ___________
What are semi-conductors
Name a noble gas
(Any one:) helium, neon. argon, kryptin, xenon, radon, ununoctium
an ion with a positive charge is called this
What is a cation
The reason why atoms have no charge
What is because the have the same number of electrons (negatively charged) and protons (positively charged) so the negative and positive cancel each other out
Elements in the same GROUP have the same number of these
What are valance electrons
The noble gases are found in this group
What is group 18
where transitional metals are found on the periodic table
in the middle
an ion with a negative charge is called this
What is an anion
How you figure the amu (mass) of an atom
number of protons + number of neutrons
Elements in the same PERIOD have the same number of these
What are electron shells (rings/orbitals/electron clouds)
All elements with an atomic number greater than _____ are man-made; they do not occur naturally
What is 92
Ruthenium's amu
101.07
The electrons on the outermost (last) electron shell are called ___________ electrons
What is valance