1. Give three facts that can be derived from the following:
I LEARNED LAST WEEK
Give three facts that can be derived from the following: 84 Po
Polonium
209 84 Po
Polonium
209
The element is Polonium.
Polonium has an atomic number of 84.
Polonium has 84 protons, 84 electrons, and 125 neutrons.

2. What I Learned Last Week
Below is the electron configuration for Polonium. How many valence electrons does Polonium have?
There are 6 valence electrons.

3. What I Learned Last Week
Is this equation balanced?
3 KOH + H3PO4 → 1 K3PO4 + 3 H20
YES. This equation is balanced.

4. What I Learned Last Week
Balance This Equation
___KNO3 + ___ H2CO3 → ___K2CO3 + ___HNO3
2 KNO3 + 1 H2CO3 → 1 K2CO3 + 2 HNO3

5. What I Learned Last Week
Write the electron configuration for Sulfur (S). Sulfur is number 16 on the Periodic Table of Elements. It has a molecular weight of 32 grams.
Sulfur (S)
16p
16n
(nucleus) (electrons) 2 8 6

6. What I Learned Last Week
The number of neutrons in 8O17 is: A. 8 B. 9 C. 7 D. 17

7. Why are enzymes needed in our cells?
a. to promote chemical reactions
b. for chemical reactions to proceed under conditions compatible with life
c. to lower activation energy requirements
d. all of the above
Answer: d

8. In cells, glucose (a six-carbon molecule) is converted into two three-carbon molecules by a reaction that releases energy. How would you classify this reaction?
a. endergonic
b. exergonic
c. decomposition
d. both B and C
Answer: d

9. a. polar covalent bonds; hydrogen bonds
Which kind of bond holds atoms in a water molecule together? What attracts water molecules to one another?
a. polar covalent bonds; hydrogen bonds
b. ionic bonds; charge interactions
c. hydrogen bonds; charge interactions
d. covalent bonds; hydrogen bonds
Answer: a

10. a. Neon has 8 electrons in its valence shell; oxygen has only 6.
Both oxygen and neon are gases at room temperature. Oxygen combines readily with other elements, but neon does not. Why?
a. Neon has 8 electrons in its valence shell; oxygen has only 6.
b. Neon cannot undergo bonding due to its polarity.
c. Neon is exergonic.
d. Neon’s molecular weight is too low to allow bonding.
Answer: a