Answer:
The mass number of an atom is equal to the number of protons plus the number of neutrons that it contains. In other words, the number of neutrons in an atom is its mass number minus its atomic number.
Explanation:
protons
The mass number of an atom is its total number of protons and neutrons. Atoms of different elements usually have different mass numbers , but they can be the same. For example, the mass number of argon atoms and calcium atoms can both be 40.
Answer:
internal fertilization
Explanation:
Internal fertilization enhances the fertilization of eggs by a specific male. Fewer offspring are produced through this method, but their survival rate is higher than that for external fertilization.
Answer : The Lewis-dot structure and resonating structure of 
is shown below.
Explanation :
Resonance structure : Resonance structure is an alternating method or way of drawing a Lewis-dot structure for a compound.
Resonance structure is defined as any of two or more possible structures of the compound. These structures have the identical geometry but have different arrangements of the paired electrons. Thus, we can say that the resonating structure are just the way of representing the same molecule.
First we have to determine the Lewis-dot structure of .
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is,
As we know that sulfur and oxygen has '6' valence electrons.
Therefore, the total number of valence electrons in = 6 + 4(6) + 2 = 32
According to Lewis-dot structure, there are 12 number of bonding electrons and 20 number of non-bonding electrons.
Hence, the Lewis-dot structure and resonating structure of is shown below.
Answer: last option, what came before the big bang?
Explanation:
The big bang theory states that the universe started as a dense nucleus of matter: a huge amount of matter concentrated in a tiny spot.
This is the conclusion of equations and evidences that prove that the universe has been and continuous to expand: since it has been expanding, there was a moment when it was as small and dense as it is possible.
So, the expansion is the result of violent explosion.
The time during which the expansion has been happening (this is how long ago the big bang occured) has been estimated thanks the the observation of the speed of recesion of the galaxies, but nothing can be told about what came before the bing bang occured.
