Answer:
atmosphere is the mixture of gases that surrounds the Earth.
Answer:
A pure substance consists only of one element or one compound and a mixture consists of two or more different substances, not chemically joined together.
So, a mixture is like mixing - let's say - sugar and rice together (dry BTW), but you can clearly see both substance are not chemically mixed together, if that makes sense. Thus, you can easily separate them out.
Answer: the percentage composition of Hydrogen is 18%
Explanation:Please see attachment for explanation
Explanation:
- When a bond is formed by transfer of electrons from one atom to another then it results in the formation of an ionic bond.
An ionic bond is generally formed by a metal and a non-metal.
For example, lithium is an alkali metal with atomic number 3 and its electronic distribution is 2, 1.
And, chlorine is a non-metal with atomic number 17 and its electronic distribution is 2, 8, 7.
So, in order to complete their octet lithium needs to lose an electron and chlorine needs to gain an electron.
Hence, both of then on chemically combining together results in the formation of an ionic compound that is, lithium chloride (LiCl).
An ionic compound is formed by LiCl because lithium has donated its valence electron to the chlorine atom.
- On the other hand, if a bond is formed by sharing of electrons between the two chemically combining atoms then it is known as a covalent bond.
For example, is a covalent compound as electrons are being shared by each oxygen atom.
Your answer is going to be a Scanning Tunneling microscope, I hope this helps!!