<span>Problem 1) From the given options the one that is proper of a chemist is the option B. testing a sample of water form a well. This activity belongs to the field called analytical chemistry which uses special techniques (instruments and processes) to study (separate, identify and quantify matter).
Problem 2) The only of the given procedures that involves a physical change in one substance is the option D. grinding chalk into a fine powder. In this process the molecules remain being the same (same atoms bonded in the number and way).</span>
I googled it and all it came up for is the Wikipedia for high school musical.
but yeah my personal answer would be: chemistry <span />
3 Chlorine ions are required to bond with one aluminum ion.
In ionic bonds, metals atoms loses all its outermost shell electrons to form a cation. While, non metal atoms gains however many electrons in order to make its outermost electron shell be 8 (or 2 if there's only one shell).
Therefore, form the periodic table, we can see that aluminum has a atomic number of 13, which makes its electron arrangement be 2,8,3. So, in order to form a aluminum ion, an Al atom must lose 3 electrons. On the other hand, Chlorine has a atomic number of 17, which means it has the electron configuration of 2,8,7. It has to gain only 1 electron to have 8 outermost shell electron.
Thereofre, 3 Chlorine atom are required to gain all 3 electrons given out by just 1 aluminum ion.
Answer:
275.3 nm is the wavelength of light required for mercury.
Mercury can not be used to generate electricity from the sun because wavelength at which mercury will emit an electron is smaller than 500 nm.
Explanation:
The wavelength of light required for mercury to emit an electron.
The wavelength of the radiation = 
Energy required fro mercury to to emit an electron = E
Energy required fro mercury to to emit an electron will the energy if the radiation = E' = 
E' = E
To calculate the wavelength of light, we use the equation:
where,
= wavelength of the light
h = Planck's constant = 
c = speed of light = 
Wavelength of the sun light in the visible region = 500 nm
500 nm > 275.3 nm
Less energy < more energy
So, this means that mercury can not be used to generate electricity from the sun.
Ion: forms when a neutral atom loses or gains electrons.
Polar molecule: a chemical species in which the distribution of electrons is not even.
Subscript: each element of an array is accessed by a number.
Coefficient: a number used to multiple a variable.
