<u>Answer:</u> The symbol of the ion formed is 
<u>Explanation:</u>
An ion is formed when a neutral atom looses or gains electrons.
- When an atom looses electrons, it results in the formation of positive ion known as cation.
- When an atom gains electrons, it results in the formation of negative ion known as anion.
Electronic configuration is defined as the representation of electrons around the nucleus of an atom.
Number of electrons in an atom is determined by the atomic number of that atom.
The element present in Group 2-A and in period 4 is Calcium (Ca)
Electronic configuration of Ca atom: 
This atom will loose 2 electrons to attain stable electronic configuration similar to Argon element (noble gas)
The electronic configration of 
Hence, the symbol of the ion formed is 
Answer:
Reducing or increasing the amount of H+ ions / hydronium (H3O+) ions
Explanation:
To reduce the pH (reducing the strength of the acid) can be done by adding a base (including a conjugate base such as bicarbonate ion) which will absorb the H+ ions either through adsorption or reaction.
Adding more H+ decreases the pH of the acid making it stronger. This can be done by adding HCL that will dissociate and increase the H+ ions.
<span>When water freezes, the molecules move farther apart. </span>
The *independent* variable is the one that you always can control. However, the dependent variables are not since they **depend** on another.