No. Of protons = mass no. - no. Of neutrons
No. Of protons = 67 - 37
= 30
No. Of electrons = 28
Zinc will have 30 protons and 28 electrons. So, it will have +2 charge
Symbol - Zn^+2
ANSWER
option B
EXPLANATION
Firstly, we will need to define the standard heat of formation
The standard heat of formation is the amount of heat evolved or absorbed when one mole of a compound is completely formed from its constituent elements under standard conditions.
From the options provided, you will see that only option B aligns with the definition of the standard heat of formation.

From the above reaction, you will see that 1 mole of water is formed from hydrogen and oxygen.
Hence, the answer is option B
The compound CBr4 has the highest melting point of 91°C
The radius of the anion is 7.413 nm
<h3>How to calculate the force of attraction between charges</h3>
The force of attraction (F) is given by the formula:
- F = (1/4π∈r²)(Zc*e)(Za*e)
where:
∈ = permittivity of free space = 8.85*10⁻¹⁵ F/m
Zc = charge on the cation = +2
Zc = charge on the anion = -2
e = charge on an electron = 1.602 * 10⁻¹⁹ C
r = interionic distance
r = rc + ra
where rc and ra are the radius of the cation and anion respectively
F = 1.64 * 10⁻⁸ N
Therefore based on the equation of force of attraction:
1.64 *10⁻⁸ = [1/4π(8.85*10⁻¹⁵)r²](2 * 1.602*10⁻¹⁹)²
r² = 5.63 * 10⁻¹⁷
r = 7.50 nm
Since r = rc + ra
where rc = 0.087 nm
thus, ra = r - rc = 7.50 - 0.087
ra = 7.413 nm
Therefore, the radius of the anion is 7.413 nm
Learn more about ionic radius at: brainly.com/question/2279609
Because the sulfur ion has a negative two charge, the formula would be Fe2S3