Answer:
Carbon - 13
Explanation:
For most of the elements other than that of hydrogen, the isotopes are named for the mass number.
Example : Carbon atoms with 6 neutrons have mass number of 12 ( as 
), so they are known as carbon-12.
Given that:
Protons = 6
Neutrons = 7
Mass = 6 + 7 = 13
So the name is Carbon - 13 . The symbol is 
Answer:
HCN, weak acid
H⁺, Br⁻, strong acid
Explanation:
Hydrocyanic acid is a weak acid, according to the following equation.
HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)
Thus, it should be written in the undissociated form (HCN).
Hydrobromic acid is a strong acid, according to the following equation.
HBr(aq) ⇒ H⁺(aq) + Br⁻(aq)
Thus, it should be written in the ionic form (H⁺, Br⁻).
The reaction occurs in a similar way as magnesium does, but much less vigorous. Strong heating is required to make iron powder burn in oxygen. The reaction gives out a yellow showery sparks and produces a black solid. iron reacts with dilute hydrocloric acid to give iron chloride and hydrogen gas.
The atomic number for Pb is 82
∴ Pb has 82 protons and 206-82 = 14 protons
The actual mass of Pb nuclei is
=(82 × mass of the proton) + (124 × mass of neutron)
=(82× 1.00728) + (124 × 1.008664) amu
= 207.6713 amu
The mass of lead which is given is 205.9744 amu
∴mass defect is
m = 207.6713 - 205.9744 = 1.6969 amu
=1.6969 × 1.66054 × 10⁻²⁷kg
=2.818 × 10⁻²⁷kg
The binding energy is E = mc²
C is the speed of light in vacuum = 2.9979 × 10⁸m/s
∴ E = 2.532 × 10×⁻¹⁰ J/mol
= 2.532 × 10⁻¹⁰ × 6.023 × 10²³ J/mol
= 1.53811 × 10¹⁴ J/mol
It's called Ice Wedging :)
