The mouth
Amongst the most vital areas to protect are the neck, face and mouth. Though keeping a set of tiger whites will be most people’s primary concern the gum and mouth guards of today also help reduce the risk of concussions and tongue injuries resulting from impacts to the jaw. The most common mouth guards available are “boil and bite” types. These are heated in order to be moulded around the user’s teeth and then form a more resistant solid on cooling. Their main component is poly(ethylene-vinyl acetate) or PEVA, made from the polymerisation of ethene with vinyl acetate.
the synthesis of PEVA by radical polymerisation
Answer:
C₂ = 0.056 ppm
Explanation:
Given data:
Initial volume = 2.0 mL
Initial concentration = 7.0 ppm
Final volume = 250.0 mL
Final concentration = ?
Solution:
Formula:
C₁V₁ = C₂V₂
C₁ = Initial concentration
V₁ = Initial volume
C₂ = Final concentration
V₂ = Final volume
Now we will put the values in formula.
C₁V₁ = C₂V₂
7.0 ppm × 2.0 mL = C₂ × 250.0 mL
C₂ = 14.0 ppm.mL /250.0 mL
C₂ = 0.056 ppm
This is an example of sphere interaction of the biosphere, hydrosphere, and lithosphere.
