Answer:- Frequency is
.
Solution:- The wavelength of electromagnetic radiation is given as 625 nm and we are asked to calculate the frequency. Frequency is inversely proportional to the wavelength and the formula used to calculate frequency when wavelength is given is:

where,
is frequency, c is speed of light and
is the wavelength.
Value of speed of light is
. We need to convert the given wavelength from nm to m.

So, 
= 
Let's plug in the values in the formula and calculate the frequency:

=
or Hz.
So, the frequency of the electromagnetic wave is
.
We are given the mineral ilmenite with a molecular formula of FeTiO3. The molar mass of the compound is equal to 151.72 g/mol. The percent titanium thus is 31.55 percent.when 750 grams of titanium is present, the mass of ilmenite is equal to 2377.18 grams
Answer: because a mole is based on Avogrado's number, which is 6.02 x 10²³ particles. It isn't possible to directly count that many particles at a time.
False. For example, changing climates will mean that some areas that experience harsh weather will soon being to experience milder weather. :)