Answer:
The formula of ammonium fluoride is NH4F.
Explanation:
1 The atoms in each ion are bonded together covalently to form a single unit.
Wrong!
⇒ The atoms in an ion compound are linked together by an ionic bond.
2 The charge is distributed over the entire ion.
Wrong!
Ions have taken in or given up electrons. This happens in the atomic shell.
3 The formula of ammonium fluoride is NH4F.
Right!
4 The formula of potassium sulfate is K2SO
Wrong!
The formula for potassium sulfate is K2SO4.
Answer: 16700 Joules
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed = ?
m = mass of sand = 2 kg
c = heat capacity = 
Initial temperature =
= 
Final temperature=
= 
Change in temperature ,
Putting in the values, we get:


16700 J of energy must be added to a 2-kilogram pile of it to increase its temperature from 40°C to 50°C
Answer:
Antoine Lavoisier.
Explanation:
I would say that it's the 18th century French chemist Lavoisier. He can arguably be called the father of modern chemistry. He proved the law of the conservation of mass and had a large part in developing the scientific method.