Answer:
Explanation:
A pure substance is something that is entirely made up of particles that are identical to each other.
Any substance that is not pure, must be a mixture.
We are surrounded by mixtures. The air is a mixture of gases . The oceans are a mixture of (mainly) water and salt. The solid earth is mostly rock, which is a mixture of different minerals.
Natural resources are substances we need and use, which occur naturally. Some come from living things, (example) cotton other are non-living (example) sand.
The opposite of a natural resource is a made resource.
Answer:
Your answer is the following...
(b)"Many valence electrons are shared between the atoms"
Explanation:
The first transistor made of gold, plastic and germanium was about the size of adult's fingernail.
Option C
<u>Explanation:</u>
The first transistor made of gold, plastic and germanium was invented in Bell laboratories. It is termed as point contact transistor. As it is made like a pointed arrow with both the sides covered with layer of gold foil. The germanium is used at the tip, just like the base and the gold foil ends as collector and emitter.
The size of this transistor is about the size of adult's fingernail. It is very small in size and it was one of its kind. Due to this small size and the working capacity by the point contact, it is termed as point contact transistor.
In an electric circuit, the free electrons are moving around. Since equal charges repel and opposite charges attract, the electrons move from the negatively charged to the positively charged pole of the voltage source.