how can I make up my low grade?
Molecules, compounds, and bonding, oh my!
Refer to entries: Compounds and Molecules, Modeling molecules, Properties of ionic and
covalent compounds
1. Forms neutral compounds and molecules (neutral means
NO CHARGE)
2. High boiling and melting points
3. Atoms remain neutral during bonding
A.
Both covalent AND
ionic
B.
Covalent
C.
Ionic
4. Generally happens between atoms of non-metals
5. Uses valence electrons to bond
6. Electrons are shared
7. Electron levels obtain noble gas status when reacted
8. Generally happens between metals and non-metals
Element formation:
The summary says, nuclear fusion occurs when
The first italicized section on the video sheet that you put a star by says, our sun is considered a
“main sequence” star. This means it is fusing...
The second italicized section on the video sheet that you put a star by says that when a star gets
to the red supergiant stage, fusion begins to form
The answer to analysis #3 should say that elements in distant stars are determined by using
telescopes with prisms and looking at...
The second italicized section on the video sheet that you put a star by says that elements
heavier than iron are fused in...
Modeling molecules *(especially the diagrams where we added dots on the bonds!)
_________When elements chemically react, they form compounds by
A. combining all of their electrons together.
B. reaching the rule of eight with valence elcctrons.
C. merging their nuclei until protons equal electrons.
how can I make up my low grade?
This model
describes
an element made up of different atoms – what is wrong with this statement?
a molecule made up of the same atoms - what is wrong with this statement?
an atom made up of one type of element - what is wrong with this statement?
a compound made up of different elements – why is this correct?
Compounds and molecules
________(pay particular attention to the color coded diagrams you made of Cl2 and H2O) The
correct statement about atoms and molecules is that
A an atom is made up of two or more molecules.
B a molecule is made up of two or more identical atoms.
C only two atoms of different kinds can be present in a molecule.
D two or more atoms of the same or different kinds can be present in a molecule.
How are ions are different from atoms?
Compared to a calcium atom, a calcium ion would have how many electrons?
THINK:
How many electrons does it have total as a neutral atom? _______
It’s a metal, so will it lose or gain valence electrons? __________ how many? ________
So...when it makes its ion, how many total electrons will it have now? _________
Is this a compound? N2 ___________ why or why not?
Is this a compound? Na___________ why or why not?
Is this a compound? BF3___________ why or why not?
how can I make up my low grade?
Is this a compound? H2S2 _________it can also be correctly described as a molecule. Why?
Modeling molecules
When calcium (row 4, column 2) reacts with chlorine (row 3, column 17), they bond ionically because
calcium is a METAL / NON-METAL and chlorine is a METAL / NON-METAL.
When carbon (period 2, group 14) reacts with oxygen (period 2, group 16), they bond covalently
because carbon is a METAL / NON-METAL and oxygen is a METAL / NON-METAL.
24. When potassium (period 4, group 1) reacts with oxygen (period 2, group 16), oxygen will...
THINK- oxygen atoms are non-metals with six valence electrons. They want to have a full set of 8.
Potassium atoms are metals that want to lose one electron
A. gain 2 electrons, while each potassium will lose 1 electron.
B. lose 2 electrons, while each potassium will gain 1 electron.
C. gain 6 electrons, while each potassium will share 1 electron.
Reading half sheet from Compounds and Molecules
The correct name for the compound LiN3 is
Lithium nitride. Why is this correct according to reading question #6?
Nitrogen lithiumide. What is wrong with this answer based on the reading questions?
Lithium nitrate. On the polyatomic ion chart, nitrate is NO3. What is wrong with choosing this
answer?
The correct name for the compound Cr(NO3)3 is
THINK: hey, there are parentheses around NO3 keeping the mulitiple atoms together. Must be a
polyatomic ion. I need to look at the chart to see what it is called!
A. Chromium nitrate.
B. Chromium trinitride.
nona”?
C. Chromium trinitrogen nonaoxide.
did I ever go over the use of prefixes like “tri” and
Why would you pick something so unfamiliar?
Reference section #9: Discovering how to read chemical formulas
How many elements are in the chemical formula Na2CO3? I’m asking for elements here. Na is an
element: sodium. Is CO an element? Why or why not? So how many elements are there?
how can I make up my low grade?
How many atoms of oxygen are there in the chemical formula Na2CO3? What number is attached to
the symbol for oxygen?
How many molecules are present in 3HNO3? In the first section of reference entry #9, how did you
write that you had three water molecules? What number told you this?
How many atoms of Nitrogen (N) are in Ca(NO3)2 ? THINK: nitrogen is inside of parentheses. I
need to use the distributive property of math for the subscript outside of the parentheses. Like,
there would be six atoms of oxygen (2 x 3). So there are _________ atoms of nitrogen ( 2 x
____ )
Modeling molecules
Lithium has one valence electron. Oxygen has 6 valence electrons. When these two
chemicals react, the resulting chemical formula is
A. Li2O
B. LiO2
C. LiO
THINK: the number that we kept saying was important for valence electrons was the number
___________ (think noble gas number of valence electrons). So, oxygen has 6 and it
wants _______. Each lithium atom only has _____ to give. So, it’s going to take
_______lithium atoms to give oxygen what it wants.
Compounds and molecules, modeling molecules, especially the notes about ions
33.
34.
Look at the diagram of helium at the right 
Helium has an atomic number of 2 and a mass of 4.
2P+
This diagram is showing a(n) ______ of helium.
1N
A.
molecule NO -this is a diagram of an ATOM
B.
ion Is it an ion by definition? ___________
C.
isotope Why is it an isotope to an atom of helium with a mass of 4?
Look at the diagram of oxygen at the right 
One oxygen atom has an atomic number of 8 and a mass of 16.
This diagram is showing a(n) ______ of the oxygen atom described 8eA.
molecule NO -this is a diagram of an ATOM
2eB.
ion Is it an ion by definition? ______________
2e-
8P+
8N
how can I make up my low grade?
C.
isotope – what is this atom’s mass? _____ is it different
than the one described? So is it an isotope?