Answer:
Vestigial Structures
Explanation:
Structures that were needed for an organism's ancestor, but no longer required for survival for the current organism. We needed our wisdom teeth and appendix in order to eat tougher foods, but now we do not need those to survive. But, we still have them.
Answer:
Choose the least electronegative atom other than H.
Explanation:
A Lewis structure consists of <em>terminal atoms</em> and one or more <em>central atoms</em>.
H can be <em>only a terminal atom</em> because it can form only one bond.
So the central atom must be either C or O.
The central atom is the less electronegative atom: C.
So, start the Lewis structure with a central C atom.
Then attach an O atom to get C-O.
Finally, attach the H atoms.
The condensed formula often gives you a clue where they go.
The formula CH₃OH implies that there are 3 H atoms on C and one on O.
The connectivity of the atoms is then as in the diagram below.
Answer:
It takes 1.32x10⁻⁷s for the concentration of A to fall by a factor of 8
Explanation:
The equation that represents a first-order kinetics is:
Ln ([A] / [A]₀] = -kt
<em>Where [A] is actual concentration, [A]₀ is initial concentration, K is rate constant (For the given problem, 1.57x10⁷s⁻¹ and t is time.</em>
<em />
As you want the time when you have [A] in a factor of 8 = [A] / [A]₀ = 1/8
Replacing:
Ln ([A] / [A]₀] = -kt
Ln (1/8) = -1.57x10⁷s⁻¹*t
t = 1.32x10⁻⁷s
<h3>It takes 1.32x10⁻⁷s for the concentration of A to fall by a factor of 8</h3>
For the first question, the correct answer among the choices listed is option A, a chocolate bar melting in hot car. It is an endothermic process because it absorbs heat energy for it to be melted. For the second question, it think the correct answer is the last option, <span>(-2222) + (-1182) - (-1144).</span>
Answer:
1. D 2. C 3. B
Explanation:
1. The product is always what is being yielded from the equation, or what is created. Since both 4H2O and 3CO2 are created from the reactants, they are both products of the reaction.
2. The Law of Conservation of Matter states that matter cannot be created, nor destroyed. Therefore, C is not true because new atoms cannot be created in a reaction.
3. The second formula is balanced, but the first is not
