Forces and Motion, Space and Time, Energy, and Nature of Matter
1)sodium chloride/common salt
2)sodium hydroxide
3)sodium carbonate/washing soda
4)sodium bi-carbonate/baking soda
5)calcium hypochlorite/bleaching power
6)hemihydrate calcium sulphate/plaster of Paris
7)calcium sulfate
8)copper sulfate
9)bororn trifluoride
10)potassium nitrate
I could only find ten examples
Answer:
Anion with 4 more electrons than protons
Explanation:
In Atomic Theory, for a given element that is defined by the number of protons the only issue that can change is the number of valence electrons.
Therefore, element ions with a positive charge have lost electrons such that the number of protons is greater than the number of electrons. For element ions with a negative charge have gained electrons such that the number of protons is less than the number of electrons.
Examples:
Elements with positive charges => cations
Ca => Ca⁺² + 2e⁻ => Oxidation half-reaction shows electrons on right of arrow indicating 'loss' of electrons. This gives calcium (Ca⁺²) having 20p⁺ with 18e⁻.
Elements with negative charges => anions
O + 2e⁻ => O²⁻ => Reduction half-reaction shows electrons on left of arrow indicating a 'gain' of electrons. This gives oxygen (O²⁻) having 8p⁺ with 10e⁻.
<u>Note on Periodic Trends of Ions</u>
It should be noted that when looking at the periodic chart, the elements to the right of the metalloid elements are typically anions with greater numbers of electrons than protons on ionization. In the same context, the elements to the left of the metalloid elements are typically cations with greater numbers of protons than electrons on ionization. Metalloids are elements highlighted in yellow => B, Si, Ge, As, Sb, & Te.
Answer: 


Explanation:
Entropy is the measure of randomness or disorder of a system.
A system has positive value of entropy if the disorder increases and a system has negative value of entropy if the disorder decreases.
1. 
As 4 moles of gaseous reactants are changing to 2 moles of gaseous products, the randomness is decreasing and the entropy is negative
2. 
As 9 moles of gaseous reactants are changing to 10 moles of gaseous products, the randomness is increasing and the entropy is positive.
3. 
As 1 mole of solid reactants is changing to 2 moles of gaseous products, the randomness is increasing and the entropy is positive.
4. 
As 4 moles of gaseous reactants is changing to 5 moles of gaseous products, the randomness is increasing and the entropy is positive
5. 
As 4 moles of gaseous reactants is changing to 1 moles of gaseous products, the randomness is decreasing and the entropy is negative.