The mass number of an atom is basically the total number of protons and neutrons.
It is OH- (hydroxide ion)
The earths gravity attracts the molecules and collects the most near the surface. They all have weight and therefore have more pressure at the surface, as well. As you go higher, the attraction becomes less and these molecules some times fly off into space. This layer of equilibrium has the least of weight or pressure.
The various pressures are measured by precision instruments called barometers or pressure sensors and expressed in inches of mercury or millibars. <span>Air has a weight too, although not very much, If you "pile" the air mile high, the bottom pressure is heavier because of all the air sitting on top of it, therefore the pressure decreases with altitude, because there is less air "piled up" </span>
<span>An analogy would be the same with water.</span>
Planes have these instruments that tells the crew the altitude above sea level they are at when flying.
Answer:
Percent error = 12.5%
Explanation:
In a measurement you can find percent error following the formula:
Percent error = |Measured value - Accepted Value| / Acepted value * 100
Based on the data of the problem, accepted value is 22.4L and the measured Value (Value of Sara) was 19.6L.
Replacing:
Percent error = |Measured value - Accepted Value| / Acepted value * 100
Percent error = |19.6L - 22.4L| / 22.4L * 100
Percent error = |-2.8L| / 22.4L * 100
Percent error = 2.8L / 22.4L * 100
Percent error = 12.5%
Answer:

Explanation:
A protein is a long chain of amino acids linked together by amide groups.
The general structure is
![\rm \left[-NHCHR-\underbrace{\hbox{CO-NH}}_{\hbox{amide group}}-CHRCO-\right]_{n}](https://tex.z-dn.net/?f=%5Crm%20%5Cleft%5B-NHCHR-%5Cunderbrace%7B%5Chbox%7BCO-NH%7D%7D_%7B%5Chbox%7Bamide%20group%7D%7D-CHRCO-%5Cright%5D_%7Bn%7D)