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.

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

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

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

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

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

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

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

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

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