Atoms And Elements Flashcards
What is the definition of an element?
A pure substance that cannot be broken down to anything simpler.
What is the definition of a compound?
Two or more elements chemically bonded in a fixed ratio.
What is the definition of a mixture?
Two or more elements or compounds are present in a variable ratio without being chemically bonded.
What is the definition of a molecule?
When two or more atoms are bonded in a fixed ratio. There can be a molecule of elements or compounds.
What is the charge of a proton?
+
What is the charge of a neutron?
0
What is the charge of an electron?
-
How do you find the number of protons in an element?
Look at the atomic number
How do you find the number of neutrons in an element?
Mass number minus the atomic number
How do you find the number of shells around an element?
The period number
How do you find the number of electrons in the outer shell?
Group number
Is the bottom or top of the alkali metals most reactive?
Bottom
Is the bottom or top of the noble gases more reactive?
Top
What is an isotope?
When an element has a different number of neutrons and protons.
What particle tells you the element?
Proton
