What does the atomic number tell us?
The number of protons in an atom.
Which family contains lithium and sodium?
Alkali metals (Group 1).
How many valence electrons does sodium have?
1.
Which behaves more like lithium: sodium or oxygen?
Sodium; both are in Group 1
An element has atomic number 11. Identify it.
Sodium (Na).
What are the horizontal rows called?
Periods.
Which family contains fluorine and chlorine?
Halogens (Group 17).
How many valence electrons does oxygen have?
6.
Does calcium tend to gain or lose electrons when forming ions?
Lose two electrons.
An element is in Period 3, Group 17. Identify it.
Chlorine (Cl).
What are the vertical columns called?
Groups or families.
Which family contains helium, neon, and argon?
Noble gases (Group 18).
How many valence electrons does magnesium have?
2.
Which is more likely to form a positive ion: magnesium or chlorine?
Magnesium.
An element is in Group 2, Period 4. Identify it.
Calcium (Ca).
Which group contains the noble gases?
Group 18.
Which family contains magnesium and calcium?
Alkaline earth metals (Group 2).
How many valence electrons does chlorine have?
7.
What ion charge does chlorine commonly form?
-1
A main-group element has seven valence electrons and is in Period 2. Identify it.
Fluorine (F).
Why can elements in the same group behave similarly?
They have similar outer electron arrangements; main-group elements generally have the same number of valence electrons.
Why do Group 1 metals react readily with water?
They readily lose their one valence electron
Why is neon usually unreactive?
Its outer electron shell is full.
Predict how potassium behaves compared with sodium.
Both are reactive Group 1 metals that tend to lose one electron; potassium is generally more reactive.
Element X is in Group 1 and Element Y is in Group 18. Predict which is more reactive
and explain.
Element X is generally more reactive because Group 1 elements readily lose one valence electron, while Group 18 elements have full outer shells.