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WorksheetsDaily Spark Science 8 Unit 2 Test review Day 1
Total questions: 10
Worksheet time: 10mins
According to this equations, what happened to the carbon and oxygen?
They combined chemically to form a new compound
They combined chemically to form carbon and oxygen.
They combined physically to form a new mixture
They combined physically to form a new element
Ca + 2H2O → Ca(OH)2 + H2
How many different elements are involved in the chemical reaction above?
8
4
6
3
Calcium metal (Ca) can be produced by passing an electric current through molten calcium chloride (CaCl2). Chlorine gas (Cl2) is also formed. What is the balanced equation for this reaction?
2CaCl → Ca + 2Cl
CaCl2 + H2O → Ca + ClH + O2
CaCl2 + Cl → Ca + Cl3
CaCl2 →Ca + Cl2
In an experiment combining vinegar and baking soda, gas is given off. In this chemical reaction, the vinegar and baking soda are
reactants
products
elements
suspensions
If you break a piece of glass, the shape of the glass changes, but the properties in the fragments remain the same. Which of the following has occurred?
A chemical change
A temperature change
A physical change
a phase change
Which of these is a change in chemical composition?
a lake freezes solid
gravel, sand, and water are mixed
a copper bar is rolled into a flat sheet
vinegar bubbles when baking soda is added
Tearing paper is an example of a
chemical change
chemical reaction
solution
physical change
Energy released by joining nuclei of atoms together is
nuclear fission
nuclear fusion
nuclear splitting
chain reactions
The formation of an ionic bond involves the
sharing of neutrons.
transfer of neutrons.
transfer of electrons
sharing of protons.
The formation of a covalent bond involves the
transfer of electrons.
sharing of electrons.
sharing of protons.
transfer of neutrons.
