Science Review for 3rd 9 weeks test - Byrd/Columbe

Which biological molecule contains a large amount of the element nitrogen?

• carbohydrates

• lipids

• proteins

• starches

CO₂ is returned to the atmosphere by all methods EXCEPT

• combustion

• decomposition

• respiration

• photosynthesis

The by-products of cellular respiration include

• carbon dioxide and water.

• energy and oxygen.

• glucose and oxygen.

• glucose and carbon dioxide.

The burning of fossil fuels by cars and factories has most affected the ______________ cycle.

• Carbon

• Hydrogen

• Nitrogen

• Water

Balance the single replacement chemical reaction.

KI + Cl₂ ---> KCl + I₂

• KI + Cl₂ ---> KCl + I₂

• 2KI + Cl₂ ---> 2KCl + I₂

• KI + Cl₂ ---> 2KCl + I₂

• 2KI + 2Cl₂ ---> 2KCl + 2I₂

If there are 4 grams of reactant, how many grams of product are produced by the chemical reaction?

• 0 grams

• 2 grams

• 4 grams

• 8 grams

Iron combines with oxygen to form rust. Given the chemical reaction, how many grams of rust would be produced if 3 grams of reactants were consumed?

• 1

• 7

• 0

• 3

Which of the these is a balanced chemical equation?

• CO(g) + O₂(g) → CO₂(g)

• CO(g) + 2O₂(g) → 2CO₂(g)

• 2CO(g) + O₂(g) → 2CO₂(g)

• 2CO(g) + 2O₂(g) → 2CO₂(g)

Without heat from the Sun, the water cycle would

• reverse

• not work

• slow down

• not be affected

78% of Earth's atmosphere is nitrogen gas. All living things need nitrogen as a part of DNA and RNA. Yet you and I, and other living things, cannot use the nitrogen in our atmosphere directly. One type of organism is responsible for "fixing" nitrogen or helping to put it in a form so other living things can use it. That organism is

• bacteria

• fungi

• plants

• viruses