The other dude is rude wrong
The correct answer is Dmitri Mendeleev
<span>1) Humans have how many sets of teeth?
C) 4
2) Adults have how may permanent teeth?
B) 32
3) What type of food products make teeth stronger?
Cheese and Yogurt
4) What is the visible part of the tooth?
C) crown
5) What part of the tooth is harder than bone?
D) dentin
6) What part of the tooth is soft and contains the nerves?
A) pulp
7) What refers to the alignment of the teeth?
</span><span>
Occlusion</span><span>
8) The lower teeth protect what?
D) tongue
9) Malocclusion is the least common reason for referral to orthodontists.
False
10) Usually, malocclusion is hereditary.
True
11) Which type of malocclusion is commonly referred to as an overbite?
Class Two
12) Bacteria are living organisms than cause cavities.
True
13) What is the whitish film that grows on your teeth called?
Plaque
14) What is the best fighter of cavities?
Fluoride
Gingivitis is the inflammation of the
A) gums
16) Gingivitis is permanent.
False
17) Name 2 ways to fight gingivitis.
Proper Toothbrushing and Flossing
</span>Professional Dental Cleanings<span>
18) The cause of gum disease is
B) bacteria
19) Untreated, periodontitis will progress until your teeth loosen and fall out.
True
</span>
Answer:
S.
Explanation:
North and South must always be opposite of each other.
I think because each element has its own number of protons and neutrons, giving it its own atomic number and mass (correct me if I’m wrong please)
Answer:
pH = 3.3
Explanation:
Buffer solutions minimize changes in pH when quantities of acid or base are added into the mix. The typical buffer composition is a weak electrolyte (wk acid or weak base) plus the salt of the weak electrolyte. On addition of acid or base to the buffer solution, the solution chemistry functions to remove the acid or base by reacting with the components of the buffer to shift the equilibrium of the weak electrolyte left or right to remove the excess hydronium ions or hydroxide ions is a way that results in very little change in pH of the system. One should note that buffer solutions do not prevent changes in pH but minimize changes in pH. If enough acid or base is added the buffer chemistry can be destroyed.
In this problem, the weak electrolyte is HNO₂(aq) and the salt is KNO₂(aq). In equation, the buffer solution is 0.55M HNO₂ ⇄ H⁺ + 0.75M KNO₂⁻ . The potassium ion is a spectator ion and does not enter into determination of the pH of the solution. The object is to determine the hydronium ion concentration (H⁺) and apply to the expression pH = -log[H⁺].
Solution using the I.C.E. table:
HNO₂ ⇄ H⁺ + KNO₂⁻
C(i) 0.55M 0M 0.75M
ΔC -x +x +x
C(eq) 0.55M - x x 0.75M + x b/c [HNO₂] / Ka > 100, the x can be
dropped giving ...
≅0.55M x ≅0.75M
Ka = [H⁺][NO₂⁻]/[HNO₂] => [H⁺] = Ka · [HNO₂]/[NO₂⁻]
=> [H⁺] = 6.80x010⁻⁴(0.55) / (0.75) = 4.99 x 10⁻⁴M
pH = -log[H⁺] = -log(4.99 x 10⁻⁴) -(-3.3) = 3.3
Solution using the Henderson-Hasselbalch Equation:
pH = pKa + log[Base]/[Acid] = -log(Ka) + log[Base]/[Acid]
= -log(6.8 x 10⁻⁴) + log[(0.75M)/(0.55M)]
= -(-3.17) + 0.14 = 3.17 + 0.14 = 3.31 ≅ 3.3
