Answer:Number of electrons that are present in an atom is determined by the electronic configuration of that atom.
If an ion is carrying a positive charge, it means that the atom has lost electrons and if an ion is carrying a negative charge, it means that the atom has gained electrons.
For the given options:
Option A: The atomic number of hydrogen atom is 1 and the electronic configuration for  ion will be:  
Thus, this atom does not have any electrons.
Option B: The atomic number of bromine atom is 35 and the electronic configuration for  ion will be:  
Thus, this atom has 36 electrons.
Option C: The atomic number of aluminium atom is 13 and the electronic configuration for  ion will be: 
Explanation:
 
        
             
        
        
        
The biggest reason is radioactive wastes. Nuclear power generated radioactive wastes like Uranimum, plutonium and amercium that inhibits gene expression and causes cancer to the environment. Nuclear plants use to release these wastes into the oceans, and it causes fishes to exhibit gender change, 3 eyes, 2 tails etc. The impact on human shows signs of serious blood, liver and lung cancers. 
There are currently no way to get rid of these wastes as they take hundred thousands of years to decompose. 
Another reason is they cause a small amount of green gas emission. Releases CO2 to the sky. They exhibit radioactive gas emission as well (causes cancer) .
        
             
        
        
        
The chemical reaction would be as follows:
<span>2Na + S → Na2S
We are given the amount of the reactants to be used in the reaction. We use these to calculate the amount of product. We do as follows:
45.3 g Na ( 1 mol / 22.99 g ) = 1.97 mol Na
105 g S ( 1 mol / 32.06 g ) = 3.28 mol S
The limiting reactant would be Na. We calculate as follows:
1.97 mol Na ( 1 mol Na2S / 2 mol Na ) (78.04 g / mol ) = 76.87 g Na2S produced</span>
        
             
        
        
        
The appropriate answer is they decrease the potential energy difference between reactant and product. They do this by bringing products and reactants together at the active site on the enzyme molecule. Enzymes are biological catalysts. They increase the rate of a chemical reaction without being used up in the reaction itself. So one molecule of an enzyme is used many times to catalyze the reaction of other molecules. 
        
             
        
        
        
Answer:
At 0.58 L of 0.540 M NaOH solution contain 12.5 g NaOH.
Explanation:
Given data:
At volume = ?
Mass of NaOH = 12.5 g
Molarity of solution = 0.540 M
Solution:
First of all we will calculate the number of moles of sodium hydroxide.
Number of moles = mass/molar mass
Number of moles = 12.5 g / 40 g/mol
Number of moles = 0.3125 mol
Volume of NaOH:
Molarity = number of moles / volume in L
Now we will put the values.
0.540 M = 0.3125 mol / volume in L
volume in L = 0.3125 mol / 0.540 mol/L
volume in L = 0.58 L