Select the statements that are correct about a group. the elements in each group have similar chemical properties. the elements in each group have identical physical properties. the atomic number of each element increases by 7 down through the group. each member of the group has the identical electron configuration in the outer shell.

The elements in each group have similar chemical properties.

Explanation:

This is correct because all elements in a group have a similar electron configuration in the outer most shell, therefore they will have similar chemical properties.

Option A as well as Option D are correct statements.

Explanation:

Each member of the group has the identical electron configuration in the outer shell For example VIIA or 17th  group of the periodic table contain Halogens that are Fluorine, Chlorine, Bromine, Iodine and Astatine.

All these elements have same number of valence electrons in its outer shell that is 7.

For example F-9

Cl-17

Hence the general electronic configuration of halogens for the Valence shell is

Because of this reason the elements in a group have similar Chemical properties since electrons play a role in the chemical property of an element.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles