1. Which of the following species determines the chemical properties of an atom? A. Electron
B. Neutron
C. Nucleus
D. Proton

2. The following glasswares are used to measure the volume of liquids except
A. graduated beaker
B. pipette
C. test tube
D. burette

 
3. Pauli exclusion principle is related to
A. quantity of electrons in the valence shell
B. filling the orbitals with lower energy first
C. the filling of degenerated orbitals
D. quantum numbers of electrons

Question 1: (A)

The number of electrons determine the chemical properties of an atom.

Question 2:  (C)

Test tube cannot measure the volume of liquids rather they are used in chemical reactions

Question 3: (D)

Pauli's Exclusion Principle states that no two electrons in the same atom can have identical values for all four of their quantum numbers.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

c. electrical charges of ionic bonds.