Response: Option A) The lattice energy rises as cations become smaller, as demonstrated by LiF and KF.
Clarification: It has been observed that the lattice energy is largely determined by two primary factors regarding ionic solids:
i) The ionic charges - An increase in the charge of the ions corresponds to an increase in lattice energy.
and
ii) The size or radius of the ions - As the ionic size grows, the lattice energy diminishes accordingly.
Therefore, in this context, the latter factor is evident. Thus, it can be concluded that as cation sizes decrease among ionic solids, the lattice energy increases.
Answer:
Explanation:
In a desert cave, an artifact has been discovered. The anthropologists investigating this artifact want to determine its age. They note that the current activity level of the artifact is 9.25 decays/s, and the carbon mass present is 0.100 kg. To ascertain the artifact's age, they will employ specific constants:
r=1.2
The formula for carbon 14 activity is
where,
is the initial activity of the substance
Now, solve for t
since,
Thus, the age of the artifact is
to two significant figures = 6300 years
Answer:
Explanation:
a) Iron has the tendency to undergo rusting -- this is a chemical property as it involves a reaction with water and air.
b) Precipitation in industrialized areas often has an acidic nature -- this is also a chemical property due to its interaction with bases or metals.
c) Hemoglobin is red in color -- this is a physical property since it doesn't entail any chemical reactions.
d) When water is left out in sunlight, it evaporates gradually -- this is a physical property because the process can easily be reversed, classifying it as a physical change.
e) During photosynthesis, plants convert carbon dioxide into more complex molecules -- this demonstrates a chemical property since it involves chemical reactions.
