Periods & Groups
Vertical columns on the periodic table are called
Groups
Electrons found in the outermost shell are called these.
Valence Electrons
What does the nucleus of an atom contain?
Protons and Neutrons
The variable you change in an experiment is the…
Independent variable
Group 1, Period 2
Lithium
Horizontal rows on the periodic table are called these.
Periods
How many valence electrons does a Group 1 element have?
1
How many electrons can the K shell hold?
2
The variable you measure is the…
Dependent Variable
Group 17, Period 3
Chlorine
What does the period number tell you about an element?
The number of electron shells
Which group has 7 valence electrons?
17
How many electrons can the L shell hold?
8
In “How does sunlight affect plant growth,” what is the dependent variable?
Plant growth
Group 2, Period 4
Calcium
What is similar about the elements in the same group?
They have similar properties and characteristics
Which group has a full outer shell and is not reactive?
18
How do you find the number of neutrons in an atom?
Subtract the atomic number from the rounded atomic mass
Why do controlled variables matter in experiments?
To keep the experiment fair, if you change too many variables you will not know what is causing the outcome
3 electron shells, 2 valence electrons
Magnesium
What does the group number (1–2, 13–18) tell you?
The number of valence electrons
Why are Group 17 and Group 1 elements highly reactive?
They very close to having a full or empty outershell
An atom has 2 electrons in the first shell and 6 in the second. What is the element?
Oxygen
In a graph, which variable is on the x-axis (horizontal) and which is on the y-axis (vertical)
Temperature
3 shells and 7 valence electrons
Chlorine