Answer:
Gamma decay/radiation
Explanation:
Gamma radiation has no mass and no electrical charge which means no change in the atomic number or mass number when gamma rays are emitted.
Most scientific questions are developed from Observations.
pH solution = 8.89
<h3>Further explanation</h3>
Given
The concentration of HBr solution = 1.3 x 10⁻⁹ M
Required
the pH
Solution
HBr = strong acid
General formula for strong acid :
[H⁺]= a . M
a = amount of H⁺
M = molarity of solution
HBr⇒H⁺ + Br⁻⇒ amount of H⁺ = 1 so a=1
Input the value :
[H⁺] = 1 x 1.3 x 10⁻⁹
[H⁺] = 1.3 x 10⁻⁹
pH = - log [H⁺]
pH = 9 - log 1.3
pH = 8.89
Zinc carbonate has the chemical formula : ZnCO3 and the equation for thermal decomposition is:
ZnCO3 .................> ZnO + CO2
1 mole of ZnCO3 produces one mole of ZnO
From the periodic table:
molar mass of zinc = 65.38 gm
molar mass of carbon = 12 gm
molar mass of oxygen = 16 gm
molar mass of ZnCO3 = 65.38 + 12 + 3(16) = 125.38 gm
molar mass of ZnO = 65.38 + 16 = 81.38 gm
125.38 gm of ZnCO3 produces 81.38 gm of ZnO, therefore:
mass of ZnO in 375 gm = (375 x 81.38) / 125.38 = 243.4 gm
Based on the above calculations, the correct answer is 243 grams
