Question is incomplete, the complete question is as follows:
A student wants to examine a substance by altering the bonds within its molecules. Which of the following properties of the substance should the student examine?
A. Toxicity, because it can be observed by altering the state of the substance
B. Boiling point, because it can be observed by altering the state of the substance
C. Toxicity, because it can be observed by replacing the atoms of the substance with new atoms
D. Boiling point, because it can be observed by replacing the atoms of the substance with new atoms
Answer:
B.
Explanation:
A student can examine a substance without altering the bonds within the molecules by examining its boiling point.
The boiling point is the property of a substance, at which the substance changes its state, which is from solid to liquid, liquid to gas and others. So, examining the boiling point will alter the bonds within the molecules as the state of substance will change.
Hence, the correct answer is "B".
It is true that the iron recommendation for girls exceeds that of boys during adolescence.
During an adolescence, girls and boys require iron for a large growth spurt and the gain of adult phenotypes and biologic rhythms.
In this period of the life, iron recommendation increase in both girls and boys, because of the increase in lean body mass, the expansion of the total blood volume, the increase and start of menstruation at girls.
Iron is essential for oxygen transport, red blood cell creation, cognitive performance and immunological function.
The overall iron requirements for girls are up to twice as boys.
More about adolescence: brainly.com/question/13528489
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This problem is providing us with the molality of a solution of calcium iodide as 0.01 m. So the most likely van't Hoff factor is required and theoretically found to be 3 due to the following:
<h3>Van't Hoff factor:</h3>
In chemistry, the correct characterization of solutions also imply the identification of the ions it will release in aqueous solution. For that reason, the van't Hoff factor gives us an idea of this number, according to the formula the solute has got.
In such a way, for calcium iodide, we write its ionization equation as shown below:
Assuming it is able to ionize due to the low molality, because if it was higher, then it won't ionize. Hence, since we have three moles of ion products, one Ca²⁺ and two I⁻, we can conclude the van't Hoff factor would be 3, although calculations may lead to a different, yet close result.
Learn more about the van't Hoff factor: brainly.com/question/23764376
The experimental control is the standard used as a comparison for the experimental groups.
For example, you may be trying to find out how different types of disinfectants affect bacterial growth. The control group would receive <em>no</em> disinfectant whereas the experimental groups would be the ones on which the disinfectants were tested.
Hope this makes sense!
Answer:
At -13 
, the gas would occupy 1.30L at 210.0 kPa.
Explanation:
Let's assume the gas behaves ideally.
As amount of gas remains constant in both state therefore in accordance with combined gas law for an ideal gas-
where 
and 
are initial and final pressure respectively.
and 
are initial and final volume respectively.
and 
are initial and final temperature in kelvin scale respectively.
Here 
, 
, 
, 
and 
Hence 
So at -13 , the gas would occupy 1.30L at 210.0 kPa.
