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".
Answer:
2.1 x 10^24 Cr ions
Explanation:
You need to multiply the 3.5 mol by the Avogrado's number (6.022 x 10^23) to get your answer.
The powder sugar because has more contact area
Answer: Option (d) is the correct answer.
Explanation:
An atom or element which has the ability to readily gain an electron will have high electronegativity.
Both Beryllium and Calcium are alkaline earth metals and hence they are electropositive in nature.
Whereas both iodine and nitrogen are electronegative in nature. But across the period there is an increase in electronegativity and down the group there is a decrease in electronegativity.
Nitrogen belongs to period 2 and iodine belongs to the bottom of group 17. Thus, we can conclude that nitrogen is more electronegative than iodine.
Answer: Heat of the solution = mass water × specific heat water × change in temperature
mass water = 260ml (1.00g/ml ) = 260g
specific heat of water = c(water) = 4.184J/ g°C
Heat change of water = final temperature - initial temperature
= 26.5 - 21.2
= 5.3 °C
H = 260 g ( 4.184J/g°C ) (5.3°C) = 5765J
Molar heat = 
= 16473J/mol
Explanation: finding molar heat requires first to look at specific heat of water and the change of water temperature
