Answer:
all together you have 13
Explantation:
you have to add all them together
Answer:
D. A²⁺
Explanation:
Element from Group 2A -
The element of group 2A are known as the alkaline earth metals ,
The elements of this group are - beryllium (Be) , magnesium (Mg) , calcium (Ca) , strontium (Sr) , barium (Ba) , and radium (Ra).
The valence shell of these elements have two valence electrons and therefore , if the element need to stabilizes itself , it need to lose these two electrons and attain noble gas configuration,
Therefore ,
After losing the two electrons , the element becomes A²⁺.
Hence , the ions are symbolized as A²⁺.
We have to determine if the given compound is soluble or insoluble in water.
The given compound is copper (II) hydroxide, 
. According to the solubility rules the hydroxides of all metal ions are insoluble except that of ammonium and the alkali metal ions. So copper(II) hydroxide will be insoluble in water. In aqueous solution, copper (II) hydroxide would exist as a sparingly soluble compound in which the undissociated compound remains in equilibrium with the ions 
and 
. The equilibrium would remain mostly towards undissociated form.
Therefore, is insoluble in water.
The biosphere and lithosphere, because paleontologist are interested in the history of the evolution of life. The lithosphere is the outer most crust and mantle, and the biosphere is where animals (such as humans) and plants mostly reside, both of which are spheres where artifacts and clues to the past are mostly found.
