Answer: A bike
A bike is composed of various simple machines. It has a wheel and axle as one component, and it also has screws to hold the various parts together, along with levers and pulleys that are connected to the pedals. So all of these simple machine concepts work together to help transport the rider from point A to point B.
The other answer choices of screw, inclined plane, and lever, are fairly simple machines that don't have many things going on at once compared to a bike.
Answer:
5.17.
Explanation:
<em>∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.
</em>
[OH⁻] = 1.5 x 10⁻⁹ M.
∴ [H₃O⁺] = 10⁻¹⁴/[OH⁻] = 10⁻¹⁴/(1.5 x 10⁻⁹ M) = 6.66 × 10⁻⁶ M.
∵ pH = - log[H₃O⁺]
<em>∴ pH = - log(6.66 × 10⁻⁶ M) = 5.17.
</em>
4 Hydrogen Atoms should be correct. Because the 4 infront of it signifies the amount of hydrogen. It would also be 4 hydrogen atoms if it were written as H4N3, because the 4 is still around the H (as long as the 4 is under scored)
<span>Water is a polar molecule. If a solute dissolved in water is polar molecule, it will dissolve in water. If a solute dissolved in water is non-polar like oil it will not dissolve in water. Polar dissolves in polar.</span>
Na is the elemental abbreviation for sodium, and Cl is the abbreviation for chlorine.
When the two are combined, you get sodium-chloride, or table salt.
Hope that helped =)