Explanations:
<u>Question</u> <u>1:</u> Lithium in 20.00+ g is C. or D., but 25.00+ g is D. which means this is the correct option.
I am unsure of <u>Question</u> <u>2</u>. I don't think it is mole though.
<u>Question</u> <u>3:</u> Boron in 25.00-30.00 g is B. or D., but 25.00 g would be C.
<u>Question</u> <u>4:</u> 2.393 x 1024 atoms of Oxygen is 63.58 mole O. I don't know for sure, but I think this is correct.
<u><em>I am NOT professional. There is a chance I am incorrect. Please reply to me if I've made a mistake.</em></u>
Energy can be conserved by efficient energy use.
Answer: Option A
<u>Explanation:</u>
Energy can be transferred from one form to another, but it cannot be destroyed or created. So it can be conserved if efficiently used. Thus efficient usage of energy lead to conservation of energy. Due to conservation of energy, the forces can be renewable and non-renewable.
So, we should know how the input energy can be completely converted to another form of energy leading to efficient usage of energy without any loss. As if there is no loss, input energy will be equal to output energy leading to 100% efficiency.
The temperature that must be to freeze the solution would be -21.1 ° C.
<h3>How to calculate the freezing temperature of this solution?</h3>
To calculate the freezing temperature we must take into account the following information.
- Solution with a salt concentration of 10% is frozen at -6°C
- Solution with a salt concentration of 20% is frozen at -16°C
- Solution with a higher concentration is frozen at -21.1°C
According to the above, it can be inferred that the puddle has a 50% concentration of salt because they had 12 kg of water and 6 kg of salt.
So the lowest freezing temperature would be 21.1°C because the puddle is 50% concentrated.
Note: This question is incomplete because there is some missing information. Here is the missing information:
- A 10% salt solution freezes at about 20°F (-6°C), and a 20% solution freezes at 2°F (-16°C).
- The lowest freezing point obtainable for salt solutions is −21.1 °C
Learn more about freezing in: brainly.com/question/14131507