What are the three subatomic particles?
Protons, neutrons, and electrons.
What is the charge of a proton?
+1 (positive).
What is the charge of a neutron?
0 (no charge).
What is the charge of an electron?
-1 (negative).
Where are protons and neutrons located?
In the nucleus.
Where are electrons located?
In electron shells around the nucleus.
What is the atomic number?
The number of protons in an atom.
What does the atomic number tell you?
The element and the number of protons (and electrons if neutral).
What is the mass number?
The total number of protons and neutrons.
How do you calculate neutrons?
Mass number minus atomic number.
What is an isotope?
Atoms of the same element with different numbers of neutrons.
What is an atomic mass unit (amu)?
A tiny unit used to measure atomic mass based on carbon-12.
1 amu is approximately equal to what?
The mass of one proton or one neutron.
How many electrons fit in the first shell?
2 electrons.
How many electrons fit in the second shell?
8 electrons.
How many electrons fit in the third shell (Grade 9 model)?
8 electrons.
What are valence electrons?
Electrons in the outermost shell.
Why are valence electrons important?
They determine reactivity and bonding.
How do you draw a Bohr model?
Put protons and neutrons in the nucleus and fill electron shells from the inside out.
How many electrons does a neutral atom have?
The same number as protons.
How is the periodic table arranged?
By increasing atomic number.
What are groups on the periodic table?
Vertical columns with similar properties and same number of valence electrons.
What are periods on the periodic table?
Horizontal rows that show the number of electron shells.
Where are metals located on the periodic table?
On the left and middle.
