Atoms
Vocabulary
The Periodic Table
Atomic Mass
Periods & Groups
Elements
100
Protons have this charge
postive
100
One- or two-letter symbol for an element
atomic symbol
100
Organization of the elements that shows the repeating patterns of their properties
Periodic Table
100
Atomic mass is the average number of _______ and ________ in an element's atom.
protons and neutrons
100
Which group has elements like Argon, Helium, and Radon?
Noble Gases (column 18)
100
What is the smallest element on the periodic table?
Hydrogen
200
Subatomic particles that surround the nucleus
Electrons
200
Number of protons in a specific element
atomic number
200
The largest of the 3 main classes of elements
metals
200
Number of neutrons in this element
12 neutrons
200
Elements with similar chemical properties
groups or families
200
A noble gas that is used to inflate balloons
Helium
300
Besides protons, these subatomic particles are found in an atom's nucleus
neutrons
300
Horizontal row of elements on the periodic table
period
300
The periodic table is organized by increasing _________.
atomic number.
300
What amu stands for
atomic mass unit
300
On a periodic table, the periods represent
How many electron shells an atom has
300
This element makes up 78% of Earth's atmosphere
Nitrogen
400
The charge of an atom's nucleus
positive
400
Family of elements in the columns on the periodic table
group
400
Who is credited with developing the first periodic table.
Dmitri Mendeleev
400
An atom’s mass number is 210 and its atomic number is 85. How many neutrons does the atom have?
125
400
Which group contains the most reactive elements?
Alkali metals (column 1)
400
Most metals are solid at room temperature. An exception is _________
Mercury
500
Which part of an atom make up most of its volume?
electron cloud
500
Have some properties of metals and some of non-metals
metalloid
500
Sometimes called rare Earth metals, these elements are found on the top row under the periodic table
Lanthanides
500
Atoms with the same number of protons but a different number of neutrons
isotope
500
Name of non-metals that mean "salt-forming"
Halogen
500
Proteins, fats, and DNA all contain this element
Carbon