Fifteen grams of a liquid plastic are frozen in a physical change that increases the volume. What can be known about the plastic after the change?
A) It will weigh more than 15 grams.
B) It will have an increased density.
C) It will still weigh 15 grams.
D) It will still have the same density.
I'd like an explanation rather than an answer, if possible. I just don't understand this question.
There are two bits of information here. First, you know the material weighed 15 grams. Second, you know it increased in volume. You must address both of those.
In the answers, both a and c deal with mass. a says it weighs more; c says it weighs the same. Do you think freezing anything causes the mass of it to change. Of course not. So c must be correct.
Both b and d deal with density. b says it increases; d says it stays the same. You know density = mass/volume. You know mass is 15 grams and it doesn't change. The statement in the problem says volume increases. So if the denominator of d = m/v gets larger what happens to the density. It gets smaller. So neither b nor d are correct. The only correct answer there is c. Do you have trouble seeing that the mass doesn't change. Suppose we have a piece of paper that has a mass of 15 g and cut it into two pieces. Guess what. The two pieces still have a mass of 15 g. What if we put it in the freezer at -20. It still has a mass of 15 g. What if we burn the two pieces of paper. Burning the paper converts it into CO2(a gas), water (a gas at burning temperatures), and leaves charred paper pieces. If we collect the charred paper remnants, and the water, and the CO2 gas all of that will weigh 15 g. Hope this helps.
The given information states that the liquid plastic is frozen, resulting in a physical change that increases the volume. From this, we can analyze the options:
A) It will weigh more than 15 grams: Since there is no mention of any additional material being added to the plastic, freezing the plastic should only result in a change in volume, not in an increase in mass. Therefore, this option is unlikely.
B) It will have an increased density: When a substance freezes and expands, the molecules become more spread out, leading to a decrease in density. So, this option is incorrect.
C) It will still weigh 15 grams: Changing the volume of a substance does not alter its mass unless additional material is added or removed. Since it is stated that 15 grams of plastic is frozen, the mass of the plastic should remain the same. This option seems plausible.
D) It will still have the same density: As discussed in option B, freezing the plastic is likely to decrease its density, as the volume increases while the mass remains the same. Therefore, this option is incorrect.
Considering the explanations provided, we can conclude that option C) It will still weigh 15 grams is the most reasonable choice.
The question is asking about the changes that occur when a liquid plastic freezes, specifically regarding its weight and density.
When a liquid plastic freezes, it undergoes a physical change called solidification. During solidification, the molecules of the plastic align in a more organized manner, resulting in a decrease in volume. This means that when the liquid plastic freezes, it occupies less space than it did in its liquid state.
Now let's evaluate the given answer choices:
A) It will weigh more than 15 grams.
Since the plastic is freezing, there is no addition or removal of any material. Therefore, the weight should remain the same.
B) It will have an increased density.
As the volume of the liquid plastic decreases during solidification, while the mass remains constant, the density of the plastic increases. Therefore, the answer choice could be true.
C) It will still weigh 15 grams.
As mentioned earlier, there is no addition or removal of any material during solidification. Therefore, the weight of the plastic will remain the same.
D) It will still have the same density.
Based on what we discussed earlier, the volume decreases during solidification, resulting in an increased density. Therefore, the answer choice is unlikely to be true.
Considering the above analysis, the correct answer is likely B) It will have an increased density.