Boric acid, H3BO3, in aqueous solution would only give out one H+ ion. As it is also produce OH ion and by hydrolysis it produces one proton. <span>All the boron compounds (BX3) are having only 6 valence electrons in it and should follow the octet rule by taking another electron.</span>
B(OH)3 + 2 H2O → B(OH)4− + H3O
Chlorofluorocarbons and other halogenated ozone depleting substances are mainly responsible for man made chemical ozone depletion.
Answer:
m = 31.284 grams
Explanation:
Given that,
The dimension of a magnesium block is 2.00 cm x 3.00 cm x 3.00 cm.
The density of magnesium is, d = 1.738 g/cm³
We need to find the mass of the magnesium block. We know that the density of an object is given by its mass per unit its volume. So,

So, the mass of the block is 31.284 grams.
Answer:

Explanation:
Alkaline earth metals are in group 2. The number of valence electrons of elements in group 2 is 2.
T = 20 % : 20 / 100 = 0.2
m1 = solute
m2 = Solvent
T = m1 / m1 + m2
0.2 = 500 g / 500 g + m2
0.2 * ( 500 + m2 ) = 500
0.2 * 500 + 0.2 m2 = 500
100 + 0.2 m2 = 500
0.2 m2 = 500 - 100
0.2 m2 = 400
m2 = 400 / 0.2
m2 = 2000 g of water
hope this helps!