Safety in the lab
What is the most important piece of protective equipment you should wear to protect your eyes in the lab?
safety goggles
In the reaction: Hydrogen + Oxygen → Water, what are the reactants?
hydrogen and oxygen
What is the center of an atom called?
nucleus
Salt dissolved in water is an example of what type of matter?
mixture
What element is the most common in the human body?
Options:
A. Oxygen
B. Nitrogen
C. Carbon
D. Calcium
E. Hydrogen
F. Iron
A. Oxygen
A bottle of a corrosive chemical is spilled on your skin. What is the first thing you should do to minimize harm?
rinse the affected area with plenty of water
Identify the mistake in this reaction:
Sulfuric acid + iron=Iron sulfide + hydrogen
The = must be an arrow
How many protons does an oxygen atom have?
8
Pure oxygen gas is an example of what type of matter?
element
The Eiffel Tower can grow by how many centimeters during hot weather?
Options:
A. 5 cm
B. 10 cm
C. 15 cm
D. 20 cm
E. 25 cm
F. 30 cm
B. 10 cm (Metal expands in heat.)
You notice a cracked beaker while heating a chemical solution. What should you do to prevent accidents?
turn off the heat source, remove the damaged beaker, say it to the teacher.
A chemical reaction changes the substance chemically, but a physical change does not. Boiling water is an example of what type of change?
a physical change
Name the subatomic particles found in the nucleus of an atom.
protons and neutrons
A material contains both nitrogen gas and oxygen gas. What type of mixture is this?
a mixture of elements
Which of the following is the main reason why we see lightning during a storm?
A. Air pressure changes
B. Electrical discharge between clouds and the ground
C. Temperature changes
D. Sound waves moving through the air
E. Sunlight shining through clouds
F. Movement of water vapor
A student ignored the lab rule of tying back long hair and got their hair caught in a Bunsen burner flame. How could this have been avoided?
always secure loose clothing and hair before working in the lab
Burning magnesium produces a bright flame. What is the chemical name of the product formed?
magnesium oxide
What is the symbol for the element gold?
Au
Carbon dioxide is made up of carbon and oxygen chemically bonded. What type of matter is this?
a compound
A single strand of human hair can hold up to how many times its weight in water?
A. 5 times
B. 10 times
C. 50 times
D. 100 times
E. 200 times
F. 500 times
B. 10 times
In a school lab, a student accidentally spilled a small amount of acid on their hand. Instead of telling the teacher, they tried wiping it off with a tissue. Later, they experienced burning and redness on their skin. What should the student have done to avoid this injury?
Options:
A. Immediately rinse their hand with plenty of water.
B. Report the spill to the teacher right away.
C. Use a paper towel to wipe the acid off.
D. Wait to see if the burning sensation goes away on its own.
E. Put on gloves after the spill to stop it from spreading.
F. Touch the spill to see how dangerous it feels.
A. Immediately rinse their hand with plenty of water.
B. Report the spill to the teacher right away.
In the word equation Calcium Carbonate + Hydrochloric Acid → Calcium Chloride + Water + Carbon Dioxide, identify all the products.
calcium chloride, water, and carbon dioxide
An atom has 6 protons, 6 neutrons, and 6 electrons. What is the name of this element?
carbon
Air contains nitrogen, oxygen, carbon dioxide, and water vapor. Is air a compound, mixture of compounds, or mixture of elements?
a mixture of compounds and elements
Which of these animals can regenerate lost body parts?
Options:
A. Dog
B. Starfish
C. Elephant
D. Rabbit
E. Whale
F. Shark
B. Starfish (Some species can regenerate lost arms.)