Answer:
Rb<K<Ga<As<Se<S
Explanation:
We must remember that first ionization energy decreases down the group and increases across the period.
First ionization energy decreases down the group because of the addition of more shells which increases the distance between the nucleus and the outermost electron. Hence, Rb has a lower ionization energy that K.
Across the period, increase in the size of the nuclear charge causes the pull of the nucleus on the outermost electrons to increase thereby increasing the ionization energy. Hence ionization energy increases across the period. For this reason, the ionization energy of Ga<As<Se as shown.
After first half-life you will have 100/2=50g. After second half-life you will have 50/2=25g.
Answer:
450g of coke (C)
Explanation:
Step 1:
The balanced equation for the reaction is given below:
3C(s) + 2SO2(g) —> CS2(s) + 2CO2(g)
Step 2:
Determination of the mass of C that reacted and the mass of CS2 produced from the balanced equation.
This is illustrated below:
Molar Mass of C = 12g/mol
Mass of C from the balanced equation = 3 x 12 = 36g
Molar Mass of CS2 = 12 + (32x2) = 12 + 64 = 76g/mol.
From the balanced equation above, 36g of C reacted to produce 76g of CS2.
Step 3:
Determination of the mass of C required to produce 950g of CS2. This is illustrated below:
From the balanced equation above, 36g of C reacted to produce 76g of CS2.
Therefore, Xg of C will react to produce 950g of CS2 i.e
Xg of C = (36 x 950)/76
Xg of C = 450g
From the calculations made above, 450g of coke (C) is needed to produce 950g of CS2.
Gas and radio waves I’m pretty sure is correct
