Answer:
<h2>F=Gm1m2r=G×1×11=G</h2>
Explanation:
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Answer:
Magnesium and calcium belong to the second group i. e. alkaline earth metals. They are known as earth metals because they are extracted from the earth. They are very reactive elements. Their reactivity increases when we go from top to bottom because the outermost electrons goes farther from the nucleus i. e. atomic radius increases so less energy is needed for its removal.
Answer:
D
Explanation:
The correct thing to do in this case would be to <u>repeat the experiment.</u>
The scientist would need to repeat the experiment in order to double-check the accuracy. If the accuracy is indeed doubtful, he/she can be able to trace the source of the error by repeating the experiment.
The correct option is D.
Answer : The amount of oxygen gas collected are, 0.217 mol
Explanation :
Using ideal gas equation :

where,
P = pressure of gas =
(1 atm = 760 torr)
V = volume of gas = 5 L
T = temperature of gas = 
n = number of moles of gas = ?
R = gas constant = 0.0821 L.atm/mol.K
Now put all the given values in the ideal gas equation, we get:


Thus, the amount of oxygen gas collected are, 0.217 mol
<h3><u>Answer;</u></h3>
It makes the reaction harder to start
<h3><u>Explanation</u>;</h3>
- <em><u>Activation energy is minimum amount of energy that is required for a reaction to start. Activation energy determines the rate of a chemical reaction such that the higher the activation energy, the lower the rate of chemical reaction and vice versa.</u></em>
- The source of activation energy needed to push chemical reactions forward is obtained from the surroundings. Catalyst speed up chemical reaction by lowering the activation energy. Therefore, catalysis is the increase in the rate of a chemical reaction by lowering its activation energy.