Atoms
What is the center of the atom called?
Nucleus
What does the periodic table show?
All the known elements
Why do equations need to be balanced?
What is the formula for finding neutrons
atomic mass- atomic number (# of P)
How do we know just by looking at the periodic table how many valence electrons a atom of an element has?
We can tell by which group it is in
Group 1=1
Group 2=2
Group 13=3
Group 14=4
Group 15=5
Group 16=6
Group 17=7
Group 18=8
Can atoms change into other atoms?
O atom changing into a C atom
Noooooo!
Which direction do the periods run on the periodic table and how many are there?
The rows <-->
7
What does the arrow represent in a equation
a chemical reaction
How do you know how many electrons there are in an atom?
It is the same as the number of protons or atomic #
How may valence electrons does Oxygen have?
6
What is located in the nucleus of an atom?
protons and neutrons
Which direction do the groups run and how many are there?
Up and down
18
What are 3 things that could indicate a chemical reaction has taken place?
color
odor
gas
precipitate
temp
How are atoms held together?
bonds
Sharing valence electrons
How many valence electrons does sodium have?
1
Where are electrons located in an atom?
The electron shells, rings, or cloud
What are most of the elements on the periodic table classified as?
metal
Balance the following equation for a reaction:
Fe + Cl2 --> FeCl3
2Fe+ 3Cl2 --> 2FeCl3
What does the law of conservation of matter state?
Atoms are not destroyed or created in nature
How many valence electrons does calcium have?
2
What particles make up and atom and what are their charges?
Proton +
Electron -
Neutron 0
What 4 things does the element square on the periodic table show you?
Atomic number
Name
Atomic symbol
Atomic mass
Balance the following equation for the reaction
CO2 + O2 --> CO2 +H2O
CO2 + 3O2 --> 2CO2 +2H2O
What is the difference in an endothermic and exothermic reaction?
Endothermic- absorbs heat
Exothermic- releases heat
How many valence electrons does Nitrogen have?
How many more does it need to bond to and be happy?
5
3