Answer:
[α] = -77.5° / 
Explanation:
Given;
Mass of optically pure substance in the solution = 10 g
Volume of water = 500 mL
Length of the polarimeter, l = 20 cm = 20 × 0.1 dm = 2 dm
measured rotation = - 3.10°
Now,
The specific rotation ( [α] ) is given as:
[α] = 
here,
α is the measured rotation = -3.10°
c is the concentration
or
c = 
or
c = 
or
c = 0.02 g/mL
on substituting the values, we get
[α] = 
or
[α] = -77.5° / 
What are the options? I can try to give you an answer if options are provided.
An electron carries a negative power to the atom. in each atom, the amount of protons and electrons are usually evened out so the atom is stable. the electrons of an atom are also found on the outside ring of an atom, unlike protons and neutrons, which are inside the atom. glad to help! :)
Answer:
Explanation:
Atom X,
Neutron num = 4, Mass num = 7
Therefore, proton number = Mass num - Neutron num
= 7 - 4
= 3
Atom Y,
Neutron num = 5, Mass num = 9
Therefore, proton number = Mass num - Neutron num
= 9 - 5
= 4
1) False. Atom X belongs to group 3 while atom Y belongs to group 4
2) False. Atom X is in a column on the left of Atom Y
3) True. Atom X and atom Y belong to the same period two on the periodic table
4) Fasle. Atom X and Y are not isotopes because they do not have the same atomic number.
Isotopy is a phenomenon whereby atom of same element have same atomic number but different mass number