1) d
2) b because the independent variable is the thing you change/control in an experiment
3) c because the dependent variable is the thing being measured in an experiment
4)hmm it might be d, as c and a are both correct as different sized feeders would make it an unfair test and different types of food would as well
5) c
6) a
7) b obviously because if he activated them at different times then the ones activated last would have an advantage
<u>Answer:</u>
<em>Chemistry is the reaction between certain elements to </em><em>create a new compound</em><em> which may happen naturally but is mostly man made and hence has lot of good as well as </em><em>adverse effects.</em>
<u>Explanation:</u>
The <em>product or compound</em> that we get and the energy or outcome we receive is the ultimate result that decides whether chemical reaction that has happened is good or bad.
There are reactions that may cause pain and suffering to living beings and are also able to<em> Infuse damage and destruction</em> are are adverse nature. they can also change the course of nature hence are are <em>dangerous.
</em>
Answer:

Explanation:
Density is found by dividing the mass by the volume.

The mass of the liquid is 12.7 grams.
We know that 15 mL of this liquid was added to a 50 mL graduated cylinder. Therefore, the volume is 15 mL. The 50 mL is not relevant, it only tells us about the graduated cylinder.

Substitute the values into the formula.

Divide.

Round to the nearest hundredth. The 6 in the tenth place tells us to round the 4 to a 5.

The density of the liquid is about 0.85 grams per milliliter and choice A is correct.
The half-life of the reaction is 50 minutes
Data;
- Time = 43 minutes
- Type of reaction = first order
- Amount of Completion = 45%
<h3>Reaction Constant</h3>
Let the initial concentration of the reaction be X
The reactant left = (1 - 0.45) X
= 0.55 X
= X
For a first order reaction

<h3>Half Life </h3>
The half-life of a reaction is said to be the time required for the initial amount of the reactant to reach half it's original size.

Substitute the values

The half-life of the reaction is 50 minutes
Learn more on half-life of a first order reaction here;
brainly.com/question/14936355
Answer:
in a laboratory
Explanation:
A controlled experiment refers to the one where everything is an experiment except a single variable is held constant. A collection of information is typically taken as a control group, which is generally the ordinary state, and another group is analyzed( such as chemical reaction as per the question) in which all conditions are similar to the control group except for the variable under examination. The main benefit of a controlled experiment is that confusion over the accuracy of the results can be eliminated more easily.