Groups and Periods
What are groups and periods?
Groups are columns and periods are rows
What does the atomic number represent?
Number of protons
What are valence electrons?
Electrons on the outer most shell
What does it mean when we say "An atom is reactive?"
It is unstable and very likely to interact with another atom.
How many electrons can be on the first shell?
2
What do groups and periods tell us about atoms?
Periods: shells
What does the number at the bottom of an elements square represent?
Atomic mass
What are valence electrons used for?
Bonding
Why would an atom be reactive?
The outer shell is not full
Where is shell one in an atom?
The inner most shell
Which element is in group four? Titanium, Silicon, Zinc?
Silicon (Si)
How can we find the number of neutrons in an atom?
Subtract the atomic number from the atomic mass
How many valence electrons are in Nitrogen (N)?
5
Explain why an atom with one valence electron is more reactive than an atom with four valence electrons?
An atom with one valence electrons is closer to having a full shell because it will lose it's single valence electron - the remaining shell will be full
Which element has 10 electrons? (Assume the atom is neutral) Neon or Carbon?
Neon
How do groups and periods help us understand atoms?
They help us understand how many shells and valence electrons which will help us understand how reactive an element is.
How many protons does hydrogen have?
1
What is the number of the shell that contains the valence electrons for Sulfur (S)?
3
Why is He in group 8A if it only has 2 valence electrons?
It's outer shell is full - it only has one shell and it has 2 electrons
If Neon (Ne) has two electrons shells with ten electrons, how many are in each shell?
1: 2
2: 8
How is the periodic table ordered?
Increasing number of protons
Why do atomic masses have decimal points?
Scientists have taken the average mass of all of the atoms and their isotopes of an element
What part of an atom determines what type of element it is?
Proton