<span>Group 1 can be characterized as atoms that have 1 electron in their valence shell. This is valuable when dealing with these questions, because the loss or gain of valence electrons is what defines ionic relationships. When group 1 elements form ionic bonds with other atoms, they are extremely likely to lose their valence electron, since the nucleus has a weaker pull on it than, say, a chlorine atom has on its 7 valence electrons. The weaker pull between the nucleus and the valence electron of group 1 elements means that the radius is high, since the electron is more free to move with less pull on it. This also means that the first ionization energy is low, since it takes relatively little energy for that electron to be pulled away to another atom.</span>
Answer:
The water molecules slow down, stronger attractions form between them, and the molecules are pulled closer together.
Explanation:
In solids the packing of the particles is closer and tighter thus increasing the intermolecular attraction. This makes solids rigid with a definite shape, size and volume. On the other hand in liquids the packing of the particles is loose thus decreasing the intermolecular attraction. This makes liquids able to flow, and takes the shape and volume of the container in which they are placed.
The original concentration of the acid solution is 6.175 
10^-4 mol / L.
<u>Explanation:</u>
Concentration is the ratio of solute in a solution to either solvent or total solution. It is expressed in terms of mass per unit volume
HBr + NaOH -----> NaBr + H2O
There is a 1:1 equivalence with acid and base.
Moles of NaOH = 72.90 10^-3 0.25
= 0.0182 mol.
[ HBr ] = moles of base / volume of a solution
= 0.0182 / 29.47
= 6.175 10^-4 mol / L.
