Answer:
1 strong acid
2 yes they are dangerous
Explanation:
Since nearly all of it is dissociated in water, it is called a strong acid.
2 yes Concentrated strong acids can cause severe and painful burns. The pain is due in part to the formation of a protein layer, which resists further penetration of the acid
Answer: Th enthalpy of combustion for the given reaction is 594.244 kJ/mol
Explanation: Enthalpy of combustion is defined as the decomposition of a substance in the presence of oxygen gas.
W are given a chemical reaction:



To calculate the enthalpy change, we use the formula:

This is the amount of energy released when 0.1326 grams of sample was burned.
So, energy released when 1 gram of sample was burned is = 
Energy 1 mole of magnesium is being combusted, so to calculate the energy released when 1 mole of magnesium ( that is 24 g/mol of magnesium) is being combusted will be:

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:
B. Na+ and O2-
Explanation:
Na+ plus has 10 electrons and O2- also has 10 electrons
<span>R-COOH
-COOH is the group, that shows that the substance is an organic acid.
Answer is B. Acids</span>