A non-sandblasted rock could be rough or smooth depending on how it was formed.
A sandblasted rock should be much smoother, since the sand blasts away any rough edges. It will, however, be slightly smaller due to losing those edges.
The boys can arrive at the conclusion that as temperature increases, a greater mass of copper sulfate is dissolved in water.
<h3>What is an experiment?</h3>
An experiment is a scientific investigation that seeks to obtain cause and effect relationships. There must be a dependent and an independent variable in every experiment.
The average of the temperature readings is; 20 + 30 + 40 + 50 + 60 + 70 + 80/7 = 50
They used an interval of 10 degrees for the temperature readings. The boys should have kept the heating time the same. The independent variable in this experiment is the temperature. The boys can arrive at the conclusion that as temperature increases, a greater mass of copper sulfate is dissolved in water.
Learn more about dependent and independent variables: brainly.com/question/967776
Answer is:
4-ethyl-1-heptene.Structure of this alkene is in Word document attached.
<span>First find main chain with longest number of carbon atoms, that is chain with seven carbon atoms and it start on the right and going up the three-carbon attachment.
Main chain has double bond between first and second carbon (</span><span>the lowest number)</span><span>, so it is 1-heptene (alkene).
</span>Substituent is on fourth carbon atom, it is alkyl group with two carbon atoms (ethyl).
The volume of chlorine molecules produced at STP would be 96 dm³.
<h3>Stoichiometric problem</h3>
Sodium chloride ionizes during electrolysis to produce sodium and chlorine ions as follows:

This means that 1 mole of sodium chloride will produce 1 mole of sodium ion and 1 mole of chlorine ion respectively.
Recall that: mole = mass/molar mass
Hence, 234 g of sodium chloride will give:
234/58.44 = 4.00 moles.
Thus, the equivalent number of moles of chlorine produced by 234 g of sodium chloride will be 4 moles.
Recall that:
1 mole of every gas at Standard Temperature and Pressure = 24 Liters.
Hence:
4 moles of chlorine = 4 x 24 = 96 Liters or 96 dm³.
More on stoichiometric problems can be found here: brainly.com/question/14465605
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