Answer:
B.) 6
Explanation:
Attached below is the Lewis structure of PCl₃ . Since phosphorus (P) has 5 valence electrons and chlorine (Cl) has 7 valence electrons, there should be 26 valence electrons (5 + 7(3) = 26) in the Lewis structure.
Bonding electrons are the electrons present in the chemical bonds between two atoms.
There are 2 electrons shared in every single bond. Within PCl₃, there are 3 single bonds. As such, there are 6 bonding electrons in the Lewis structure of PCl₃.
2H₂ + O₂ ⇒ 2H₂O
<h3>Further explanation</h3>
Conservation of mass states that
<em>In a closed system, the masses before and after the reaction are the same</em>
So it can be concluded
- mass of the reactants = mass of the products
- mass cannot be created or destroyed
- The number of atoms involved in a reaction remains the same⇒ number of moles also the same
- chemical equation in balanced form
So let's see which of the several options , which one has the same number of atoms on both sides of the equation
2H₂ + O₂ ⇒ 2H₂O
H ⇒ left 4, right 4
O ⇒ left 2, right 2
so the equation is in balance and represents the Law of Conservation of
Mass
Oxygen is a pure substance, as it is composed of only a single kind of atom. Which is the oxygen atom, it cannot be broken or degraded down any further into constituents that make up the element. In terms of both chemically and physically.
Not enough information to find the volume, unless the density of the substance was given or some container of honey with a measure in centimeters cube.
The half-life of cobalt-60 is 5.26 years. After 10.52 years, 5 grams of a 20-gram sample will remain is TRUE
<u>Explanation:</u>
Mass of cobalt = 20 g
Half-life = 5.26 years
Mass remains after 10.52 years = 5 g
This can be solved by using given below formula, 
= initial mass
t = number of years from when the mass was m_0
m(t) = remaining mass after t years
Number of half-lives = 
Number of half-lives = 
Number of half-lives = 2
At time zero = 20 g
At first half-life = 
= 10 g
At second half life = 
= 5 g
The given statement is true.
