Answer:
The change in energy when a neutral atom in the gaseous state adds an electron to form a negative ion.
Explanation:
That is, it is the energy involved in the reaction
X(g) + e⁻ ⟶ X⁻(g)
For most elements, the electron affinity is negative.
However, there are two major exceptions — the values are positive for the elements of Groups 2 and 18 (note the troughs in the graph below).
Answer:
1. 266.22 g/mol
2. 168.81 g/mol
3. 223.35 g/mol
4. 199.88 g/mol
Explanation:
For you to calculate the molar mass of the salt you need to sum the molar masses of every element in the salt.
In the first salt, PdBr, the subscript 2 means that there are 2 atoms of Br. So for you to calculate the molar mass of the salt you need to sum the molar mass of Pd and 2 times the molar mass of Br, as follows:
106 g/mol + 2(79.90 g/mol) = 266.22 g/mol
In the second salt BeBr there are 2 atoms of Br and 1 of Be, so the molar mass is:
9.012 g/mol +2(79.90 g/mol) = 186.22 g/mol
In the third salt CuBr there are 2 atoms of Br and 1 of Cu, so the molar mass is:
63.55 g/mol + 2(79.90 g/mol) = 223.35 g/mol
And in the fourth salt CaBr there are 2 atoms of Br and 1 of Ca, so the molar mass is:
40.08 g/mol + 2(79.90 g/mol) = 199.88 g/mol