Alkaline earth metal are the elements present in II group in the periodic table and are known as 'Metals' and have a charge of +2.
Alkaline earth metals - Be , Mg Ca, Sr , Ba, Ra
Halogens are present in VII A group in the periodic table and are 'Non-metals' and have a charge of -1.
Halogens - F, Cl, Br, I, At
When Alkaline earth metal (metals) combine with Halogens (non-metals) the compound formed will be ionic compound and the formula of the compound will be based on the charges of the element.
When we write the formula of the ionic compound the charges of the elements get criss crossed.
For example - Mg (Alkaline earth metal) have a charge of +2 and Cl (Halogen) have a charge of -1 and when they combine to form the formula their charges get criss crossed and we will get 
or 
When an alkaline earth metal, A, reacts with a halogen, X, the formula of the Ionic compound formed should be 
Answer:
Bq/m3 (becquerels per cubic meter) or pCi/l (picocuries per litre)
Explanation:
The unit of the International System of Units identified to measure radioactive activity is Becquerelio (Bq) and equivalent to one decay per second.
The Curio (Ci) is also a radioactivity unit, which is still being used in some countries. It owes its name to chemists and chemists Pierre and Marie Curie.
It represents the amount of material in which 3.7 × 1010 atoms per second, or 3.7 × 1010 nuclear decays per second, which is roughly the activity of 1 g of 226Ra (isotope of the chemical chemical element).
The equivalence between the two is:
1Ci= 3,7 × 1010Bq
The specific radioactive activity of a radioactive gas such as radon gas is measured per unit volume and measured in Bq/m3 or pCi/l.
In this case the equivalence is:
1pCi/l= 37Bq/m3
Answer:
Distillation
Explanation:
Distillation is the process of separating the components of a liquid by using the method of selective boiling and condensation.
Since the components of the liquid have different boiling points, they would evaporate at different temperatures, thus causing the separation to occur.
So, distillation can be used to separate a mixture of milk and water.
C. An atom of helium has its valence electrons in its first energy level, it wouldn't and can't satisfy the Octet rule as it only has 2 electrons, but with 2, it has a full shell, as the first energy level can hold only 2 electrons.
It would be 6 because of the elements
