Elements in which group on the periodic table will never form any bonds?
Group 8A.
100
What is the main difference between "endothermic" and "exothermic"?
Endothermic: absorb heat
Exothermic: release heat
100
Anna dissolves 10g of sugar in water. How many moles are in the solution?
0.029 moles of sugar.
(10g/342.3g/mole)
100
List the three states of matter in order of increasing particle movement and energy.
solid, liquid, gas
200
True or False: Bromine has a higher electronegativity than Chlorine.
False. Electronegativity decreases as you go down a group.
200
Which of the following will have similar bonding properties as Fluorine?
A) Oxygen
B) Chlorine
C) Neon
D) Nitrogen
Chlorine because it is in group 7 and has 7 valence electrons like Fluorine.
200
Which of the following will slow down the rate of a reaction?
A) Mixing
B) Using small pieces of reactant
C) Decreasing Temperature
D) Stirring
C) Decreasing Temperature
200
Rainwater has a pH of 6.6. Based on this, the rainwater is considered:
A) Strongly acidic
B) Slightly acidic
C) Strongly basic
D) Slightly basic
B) Slightly acidic
200
A pencil is a solid. Which of the following is a physical property of a pencil?
A) Color
B) Burning
C) Reaction with acids or bases
D) Rust
A) Color
300
Cobalt's atomic number is 27. This means that a neutral atom of cobalt also contains ____ electrons and ____ neutrons.
27 electrons
32 neutrons
300
Rubidium has one valence electron and Sulfur has 6 valence electrons. What is the correct chemical formula for Rubidium Sulfide?
Rb2S
300
When balanced, the correct coefficients in the equation below are:
__H2O2-->__H2O+__O2
2H2O2-->2H2O+O2
300
Brandon mixes 0.5 moles of Acid with 10L of water. What's the concentration of the solution?
0.05M
(0.5moles/10L)
300
A balloon is filled with 8 moles of gas at STP. What is its volume in liters?
179.2L
400
Draw the shell model for an atom of Chlorine. Be sure to include ALL parts.
period #=#of shells=2
group #=# of valence e-=7
Nucleus with protons and neutrons, electrons in the shells around.
400
Why is N2 considered nonpolar covalent?
The electronegativity values of each N are equal so they share electrons equally.
400
Sg-256 undergoes alpha decay. What is the new isotope symbol produced by this alpha decay?
Rf-252
400
Which is heavier, one mole of Sulfur atoms or 32.06g?
Their masses are equal. One mole of Sulfur atoms weighs 32.06g.
400
Most elements on the periodic table are:
A) solids
B) liquids
C) gases
solids
500
Which element would make the best coin?:
a) Phosphorus, P
b) Silver, Ag
c) Xenon, Xe
Silver because it is the only metal in the list.
Phosphorus is a non-metal and is dull and brittle.
Xenon is a gas so it can't be used as a coin.
500
Draw the lewis dot structure for PF3. What is the name of its shape?
Trigonal Pyramid or pyramidal
500
When starting with 10g of C8H18, how much CO2 is produced? (The molar mass of C8H18 is 114.26 g/mol and CO2 is 44.01 g/mol)
2C8H18+25O2-->16CO2+18H2O
30.8 g of CO2 will be produced.
500
How many grams of KBr were used to make 3.00L of a 0.75M solution?
267.75g of KBr were used.
moles=3L*0.75M=2.25 moles
2.25moles*119.002 g/mol= 267.75g
500
A substance has a melting point of -162oC. As a substance changes temperature from -166oC to -150oC, which of the following has happened to the molecules?
A) They now vibrate in place
B) They have lower entropy
C) They have more energy
D) They are packed more closely together