Answer:
True.
Explanation:
A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.
A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;
1. Extrinsic semiconductor.
2. Intrinsic semiconductor.
An intrinsic semiconductor is a crystalline solid substance that is in its purest form and having no impurities added to it. Examples of intrinsic semiconductor are Germanium and Silicon.
In an intrinsic semiconductor, the number of free electrons is equal to the number of holes. Also, in an intrinsic semiconductor the number of holes and free electrons is directly proportional to the temperature; as the temperature increases, the number of holes and free electrons increases and vice-versa.
In an intrinsic semiconductor, each free electrons (valence electrons) produces a covalent bond.
<span>Jet streams act as an invisible director of the atmosphere and are largely responsible for changes in the weather across the globe.
Hope this helps</span>
Answer:
The answer to your question is:
Explanation:
There are two kinds of cell transport passive transportation and active transportation.
Passive transportation does not need energy because molecules move from higher concentration to lower concentration.
Active transportation needs energy because molecules moves against concentration.
a. facilitated diffusion It's an example of passive transportation so this answer is wrong.
b. passive transport Molecules move in favor of concentration so this answer is wrong.
c. osmosis is another example of passive transport so this answer is wrong.
d. simple diffusion it's another example of passive transport, so it's wrong this answer.
e. active transport this is the right answer.
Fusion reactions happen in stars
