Answer:
a) 
b) 
c) 
d) 
Explanation:
For neutral atoms:
Atomic Number (Z)= number of protons = number of electrons
Mass number (A) = number of protons + number of neutrons
For ions with positive net charge:
Number of protons = Z + net charge
For ions with negative net charge:
Number of protons= Z - net charge
a) A = 71, Charge = +3
Number of electrons = 28
Number of protons = 28 +3 =31
b) A = 35, Z = 45+35=80, Charge = -1
Number of protons =35
Number of neutrons = 45
Number of electrons = 36
Charge = Number of protons- Number of electrons =35-36 = -1
c) Charge = +4
Number of electrons = 86
Number of protons = Z = 86+4 = 90
mass number = A = 90+142 = 232
d) Charge = +2
Atomic number = Number of protons = Z = 38
mass number = A = 87
Answer:
Enthalpy is the amount of heat released or absorb. The total enthalpy can be found by subtracting the products' enthalpy by the reactants' enthalpy
I believe the answer is D.
Mg is magnesium. NO3 is nitrate. This gives you magnesium nitrate as an answer.
2)
formula equation: Pb(NO₃)₂(aq) + 2KI(aq) ----> PbI₂(s) + 2KNO₃(aq)
total ionic equation: Pb⁺² + 2NO₃⁻¹ + 2K⁺¹ + 2I⁻¹----> PbI₂(s) + 2K⁺¹ + 2NO₃⁻¹
net ionic equation: Pb⁺² + 2 I⁻¹----> PbI₂(s)
3)
formula equation: Zn(NO₃)₂(aq) + K₂CO₃(aq) -----> ZnCO₃(s) + 2KNO₃(aq)
total ionic equation: Zn⁺² + 2NO₃⁻¹ + 2K⁺¹ + CO₃⁻² ---> ZnCO₃ (s) + 2K⁺¹ + 2NO₃⁻¹
net ionic equation: Zn⁺² + CO₃⁻² ----> ZnCO₃ (s)
note: if I did not specify the state of the molecule in the reaction, you can assume they are aqueous unless state otherwise.
