Which letter represents an electron?
W
What is the difference between ionic and covalent bonds?
Ionic bonds require + and - charges (transfer e-), while covalent bonds require the sharing of electrons
Is the following reaction balanced or unbalanced? How do you know?
4Al + 3O2→ 2Al2O3
It is balanced because the mass of the reactants is equal to the mass of the products
What is the difference between fission and fusion
Fusion combines small nuclei, while fission splits large nuclei
Which model is plasma? How do you know?
Model 1 because it has electrically charged particles
Boron is what type of element: metal, metalloid, or nonmetal?
Metalloid
What is the name of the compound with the formula CaI2?
Calcium iodide
Balance the equation
_H2 + _O2 → _H2O
2H2 + 1O2 → 2H2O
What is the half-life process
The time it takes for half the atoms of a radioactive substance to decay
Which state of matter has the most molecular motion?
A gas
An atom’s reactivity is determined by the number of _________
Electrons in its outer shell
What is the formula for the reaction between Lithium and Oxygen?
Li2O
A chemical equation is balanced when….
The same number of each kind of atom appears in the reactants and in the products
How many half-lives does it take for a radioactive substance to decay until only one quarter (1/4) of the original substance remains
Two half-lives
How is the volume of gas related to temperature?
They are in direct proportion to eachother
Which element reacts most similarly to Chlorine: Sulfur or Fluorine?
Fluorine, because they have the same # of valence electrons
Unknown element W has 2 valence electrons. Unknown element X has 7 valence electrons. What is outcome when elements W and X react?
WX2
Meredith mixes together 5 grams of baking soda and 5 grams of vinegar in a test tube that is not sealed. She then weighs the product and finds that it weighs 9 grams. Matthew conducts the same experiment, except in a sealed bag. He finds that 5 grams of baking soda and 5 grams of vinegar will result in 10 grams of product. What might account for their different findings?
Some of the mass escaped from the test tube as a gas before it was massed
What is the biggest risk associated with using radioisotopes in nuclear reactors?
If the radiation were to leak out of the reactors, it could cause significant damage to living organisms
What occurs when air is subjected to less pressure?
It expands
How many protons, electrons, and neutrons are in the element below
11 protons, 11 electrons, 12 neutrons
Unknown elements W and X formed the compound W3X during a reaction. If element W has one valence electron, element X MOST LIKELY has how many valence electrons?
5
Balance the following equation
__MnO2 + __HCl → __MnCl2 + __H2O + __Cl2
1MnO2 + 4HCl → 1MnCl2 + 2H2O +1Cl2
If Bismuth-212 has a half-life of 60.5 seconds, how many grams of the sample will be left after 121 seconds?
14.75 g
When a sample of a gas is heated at a constant pressure, the average kinetic energy of its molecules (increases or decreases) and the volume of the gas (increases or decreases)
kinetic energy increases and volume of the gas increases