<span>The part of making a solution that always releases energy is the overall change in forming the solution. The answer is letter D. Although letters A, B and C can be viable answers but, it is not always the case. There are some substances that when you mix or separate them requires more energy or less energy. An example would be w</span>hen the formation (or enthalpy of formation) of carbon
dioxide is negative, it means that it releases heat to the surroundings. When
it releases heat to the surroundings, the reaction is exothermic. Another example is when you mix baking soda and muriatic acid, the resulting mixture is colder. When it is cold, it means that the reaction is endothermic. So the best answer is letter D.
Explanation:
The molar mass of the compounds are incorrect
Answer: Ionic formula will be 
.
Explanation: 
and 
ions will form a ionic compound. Ionic compounds have both metals and non-metals.
Here is a metal and is a non-metal.
The net charge on any compound must be 0.
So we need 2 phosphate ions to balance the charge on ions. Similarly we need 3 Magnesium ions to balance the charge on ions.
Criss-crossing the charges, we will get the formula as
Criss-crossing is shown in the image below.
Covalent bonds are formed when 2 neutral atoms come together to share a pair of electrons, where each atom contributes one electron each to be shared.
The covalent bond is kept together by the electrostatic attraction between the nuclei of the atoms and the shared pair of electrons.
Covalent bonds are usually formed between non metals with a small difference in their electro negativity.
the correct answer is
A. Neutral atoms coming together to share electrons
