WorksheetsChemistry Review (units 1,2,3)
Total questions: 30
Worksheet time: 49mins
Which statement accurately describes the atoms of a specific element?
An indium‚ In‚ atom contains 115 protons inside the nucleus and 49 neutrons outside the nucleus.
A scandium‚ Sc‚ atom contains 45 electrons outside the nucleus and 21 neutrons inside the nucleus.
An aluminum‚ Al‚ atom contains 27 electrons and 27 protons inside the nucleus.
A zinc‚ Zn‚ atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus.
Which statement does NOT correctly compare silicon with another element?
Silicon is a better conductor of electricity than sulfur.
Silicon conducts electricity as well as copper does.
Silicon is a solid at room temperature, but argon is a gas.
Silicon is less malleable than silver.
Which statement correctly describes the location and charge of the electrons in an atom?
The electrons are inside the nucleus and have no charge.
The electrons are outside the nucleus and have no charge.
The electrons are inside the nucleus and have a negative charge.
The electrons are outside the nucleus and have a negative charge.
A chemist made the table below to record some atomic properties of four elements.
Based on the information in the table, which conclusion about the chemical reactivity of these elements is valid?
Boron is the most reactive because it has the most protons.
Fluorine is the most reactive because it has 7 electrons in the outer shell.
Silicon is the most reactive because it has an equal number of protons and neutrons.
Gallium is the most reactive because it has many more neutrons than protons.
What is the total number of protons, neutrons, and electrons in a cadmium, Cd, atom that has a mass number of 112?
(a)
CaCO3 ---> CaO + CO2
A student listed how different parts of the body work to aid in food digestion. Which of the following is a CHEMICAL change that occurs to the food?
The reduction (gets smaller) in size of food particles as food is chewed.
The movement of food to the stomach after food is swallowed.
The breakdown of molecules of food by enzymes and acid in the stomach.
All of the above
Based on the information in the table, which of these statements is NOT TRUE?
A molecule of sorbitol contains three more oxygen atoms than a molecule of glutamine does.
A molecule of lactose contains twice as many atoms as a molecule of fructose does.
A molecule of fructose contains four more atoms than a molecule of glutamine does.
A molecule of lactose contains twice as many carbon atoms as a molecule of sorbitol does.
A student is using colored beads to make a model of aluminum sulfate Al2(SO4)3. Aluminum atoms are represented by blue beads, sulfur atoms by yellow beads, and oxygen atoms by green beads. What combination of beads should the student use for the model?
6 blue, 3 yellow, 7 green
2 blue, 1 yellow, 4 green
2 blue, 3 yellow, 12 green
6 blue, 12 yellow, 12 green
Strontium phosphate, Sr3(PO4)2, is a crystalline substance used in medicine and industry. How many phosphorus atoms are represented in the formula?
4
8
2
6
A chemical reaction in which calcium carbonate, CaCO3, is decomposed results in the production of two simpler compounds. What mass of calcium carbonate, to the nearest hundredth of a gram, is decomposed in this reaction?
(Law of Conservation of Mass applies)
6.03
615.16
49.97
1.27
Which two elements have properties in common?
Nitrogen and Phosphorous
Oxygen and Nitrogen
Sulfur and Nitrogen
How many molecules are present in the following compound:
8CH4
12
8
32
40
How many oxygen atoms are on the reactants side of the following equation?
8
2
6
9
Which of the following equations are correctly balanced?
12CO2 + H2O ---> C6H12O6 + O2
CO2 + H2O ---> 3C6H12O6 + O2
CO2 + 9H2O ---> C6H12O6 + O2
6CO2 + 6H2O ---> C6H12O6 + 6O2
How many Hydrogen atoms in 3(NH₄)₂CrO₄?
4
2
8
24
Air is made up of molecules of different gases that are not joined chemically. Which term best describes air?
compound
mixture
pure substance
element
How many molecules are in the following formula? 3C2H6
3
6
12
18
Which of the following is the best description of an electron?
No charge and the same mass as a proton
negative charge and much less mass than a proton
positive charge and much more mass than a neutron
negative charge and the same mass of a neutron
Atoms of a certain element have 11 protons and 1 valence electron. Which statement is correct?
the element is sodium and it is not reactive
the element is fluorine and it is highly reactive
the element is fluorine and it is not reactive
the element is sodium and it is highly reactive
Which process is the best example of a physical change in the digestive system?
saliva converting starch molecules into simple sugar
digestive enzymes breaking down proteins into smaller parts
intestinal bacteria converting lactose into simple sugars
teeth grinding an almond into smaller pieces in the mouth
A student is studying calcium, a highly reactive element that humans need for strong bones. Which characteristic of calcium is most closely related to its chemical reactivity?
The 20 protons in each atom of calcium
The density of calcium, which is 1.54 g/cm3
The atomic mass of calcium, which is 40.078 amu
The 2 valence electrons in each atom of calcium
The table shows the chemical formulas for four substances.
Which substances have the same number of carbon atoms?
Substances 1 and 2
Substances 2, 3, and 4
Substances 2 and 3 only
Substances 1 and 3
The equation below represents a chemical reaction that occurs in living cells.
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
How many atoms are represented in the reactants of this equation?
6
12
24
36
Seratonin is a chemical substance that acts as a neurotransmitter. It helps relay messages in the human brain. The formula for one molecule of serotonin is shown below.
C10H12N2O
How many atoms in all are in a molecule of seratonin? Enter only the number
(a)
