Answer:
Both b and d can be correct
Explanation:
Generally, diffusion does not require energy (<em>making option a wrong</em>) because it is the movement of particles from a region of high concentration to a region of low concentration hence diffusion moves particles in the direction of a concentration gradient. An example of this is the passive transport (for instance, uptake of glucose by a liver cell).
However, in some cases, when diffusion is against the concentration gradient (i.e when particles move from a region of low concentration to a region of high concentration), diffusion will require energy in a case like this (<em>making option c wrong</em>). An example of this is active transport (transport of protein called sodium-potassium pump which involves pumping of potassium into the cell and sodium out of the cell).
The explanation above shows that diffusion can require energy to move particles (in or out) of the cell through the cell membrane.
Answer:
Here's what I get
Explanation:
1. Complete structural formula
Methylpropane consists of a chain of three carbons with another carbon atom attached to the middle carbon. Enough H atoms are added to give each C atom a total of four bonds.
The complete structural formula is shown below (There is a C atom at each intersection).
2. Condensed structural formula
A condensed structural formula is designed to be typed on one line.
The molecule has three CH₃ groups attached to a single carbon atom, so the condensed structural formula is
(CH₃)₃CH
The formula is also often written CH₃CH(CH₃)CH₃ and as (CH₃)₂CHCH₃.
Examples of what can be found in each layer of the atmosphere
