Answer:
Option a: positron emission. 
 
Explanation:
In the transformation we have:
⁶⁷Ga  →  ⁶⁷Zn  
The reaction is:

For Ga to become Zn, the atom nucleus has to lose a proton, so in the given options, the reaction that involves the transformation of a proton is the option a, positron emission. 
In a positron emission, a proton becomes into a neutron and a positron:

Therefore, the correct answer is option a: positron emission.
I hope it helps you!
 
        
             
        
        
        
Answer:
From the solubility curve, which salt shows the least change in solubility as the temperature increases? NaCl
Explanation:
 
        
             
        
        
        
Answer:
The two statements are all True for group 7 and 8 elements.
Explanation:
The Group 7 elements are known as the halogens. They are reactive non-metals and are always found in compounds with other elements. Chlorine, bromine and iodine are all halogens.
Chlorine, bromine and iodine are the three common Group 7 elements. Group 7 elements form salts when they react with metals. The term ‘halogen’ means 'salt former'.
In addition to the discription given to norble gases in the question which is true, norble gases;
-      are inert gases located on the right of the periodic table.
-      have a full-set of valence electrons, so they're stable, unreactive
-      are colorless, odorless and tasteless.
-      have low melting and low boiling points.
-      can be found in small amounts in the Earth's crust and the Earth's atmosphere.
 
        
             
        
        
        
Answer:
D
Explanation:
There are only 2 ways to explain this.
distance
and brightness caused by what it is burning. 
A is true but it is not the explanation of why it is true.
B this is actually not true. Other stars would burn much more.
C It is not the largest star. In fact it is in the lower middle. 
D is the answer. 93 million miles as these things go, is not every much.