Answer:
I think no C or D
if wrong correct me plsssssss
Mark me brainliest plsss
Explanation:
December 21 marks the winter solstice in the Northern Hemisphere, but in 2020 the longest night of the year is also going to be a witness to an incredible astronomic event known as the “great conjunction”. ... This rare double planet sighting–or “Great Conjunction”–can be viewed from anywhere around the globe
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon).
Answer: Molarity of the prepared solution is 
Explanation:
Molarity is defined as the number of moles of solute dissolved per liter of the solution.

where,
n= moles of solute
= volume of solution in ml = 500 ml
moles of solute =
Now put all the given values in the formula of molarity, we get

Thus molarity of the prepared solution is 
<u>Answer:</u>
<em>An atom accepts electrons and becomes an anion.</em>
<em></em>
<u>Explanation:</u>
Atomic number = number of electrons = number of protons.
Atomic number of sodium is 11
So the atom contains 11 protons and 11 electrons
To find the number of neutrons we make use of the formula
Mass number - atomic number = number of neutrons
From the periodic table, we know mass number of sodium is 23
So number of neutron = 23 - 11 = 12.
When a sodium atom loses an electron it will have 11 positive protons and 10 negative electrons. Since 1 positive charge is more, Na becomes
.
Positively charged ion is called as cation
Chlorine's atomic number is 17 so it has 17 protons and 17 electrons.
When it gains an electrons, it will have 17 positive protons and 18 negative electrons. Since 1 negative charge is more, Cl becomes
.
Negatively charged ion is called as anion.