QUARTER 1 CHEMISTRY REVIEW

A group of researchers conducted a scientific investigation on the health status of nurses in a big hospital. Based on what you have learned about the steps of a scientific investigation, what could have started such investigation of the researchers?

• A conclusion

• An experiment

• A hypothesis

• A problem

The following are all examples of a qualitative observation EXCEPT…

• The unknown substance smells sweet according to Paul.

• Only a moderate amount of sugar is added in his experiment.

• Only a few drops of ink is measured and added in his experiment.

• Five drops of ink using a dropper was used in Matthew’s experiment making it more accurate

Which statement expresses a quantitative observation?

• Hannah is as tall as her mother.

• Kacey is thinner than her sister.

• Grace has a rounded face and is beautiful.

• Ann is a little bit taller than me. She is taller by 1 centimeter.

Joe wanted to test how the mass of a paper airplane affects the distance it would fly. To do this, he added paper clips before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly. In this experiment, what is the manipulated variable?

•  Joe    

• mass of the airplane

• type of the airplane

• distance traveled by the airplane

Daniel performed an experiment to determine how the amount of tea leaves could affect the taste of bubble tea. The same kind of tea, the same percolator, the same amount and type of water and the same boiling time. What variable is referred to in the second sentence?

• control

• dependent

• independent

• manipulated

Which part of the scientific method would you most likely find this statement: If you add detergent in a mixture of oil and water, then, they will mix.

• conclusion

• experiment     

• hypothesis

• observation

A farmer wanted to know if a new brand of fertilizer would be good for his crops. He fertilized all his okra plants with new fertilizer but did not put any fertilizer on his tomato plants. He left the plants in the same condition. His okra did not grow very well, but his tomatoes were big and healthy. He concluded that the new fertilizer was not good. What is wrong with his experiment? The farmer’s/farmer _________.

• observation was wrong

• used two different plants

• did not use enough okra and tomatoes

• did not use enough fertilizer on the okra

Water is formed by the chemical combination of hydrogen gas and oxygen gas as shown in the following equation:   2H₂ + O₂ ---- 2H₂O.

Which is the compound in the above chemical reaction?

• H₂      

• O₂

• H₂O

• 2H₂

There are elements with the names: californium, germanium, gallium and berkelium.  Where did these names of such elements originate?

•                                  Latin names

• Famous people

• meanings of the word

• places where the elements were discovered

Most people wanted to make their food delicious by adding spices or substances like vetsin when they cook their food. What is the chemical name of vetsin?

• citric acid

• sodium chloride

• sodium hydroxide

• monosodium glutamate