The answer is C :
It controls the entry and exit of substances.
Answer: Titanium has 22 protons
Explanation: If an atoms donates 4 electrons, it forms cation with charge +4. So original atom have 22 electrons and because atom is neutral, it has 22 protons. Number of neutrons does not matter, there are more neutrons than protons in heavier atoms.
Answer:
the temperature of the star
Explanation:
The color of stars usually indicates the temperature of the star.
A star that is relatively cold usually shows a typical red color.
The hottest stars have a blue color.
- These star colors have been used by astronomers to determine their temperature.
- A broad spectrum between blue, the hottest color, and red the coldest is used.
- Class O stars are usually the blue colored ones
- Class M is the coldest with red color
Answer:
C.) Argon
Explanation:
This is because ionisation energy increases as we move from left to right in a period. Argon presents in the right most column and Argon is a novel gas and has 8 electrons in outermost orbital. So, it is highly stable. I hope I helped! ^-^
Answer:
The two statements are all True for group 7 and 8 elements.
Explanation:
The Group 7 elements are known as the halogens. They are reactive non-metals and are always found in compounds with other elements. Chlorine, bromine and iodine are all halogens.
Chlorine, bromine and iodine are the three common Group 7 elements. Group 7 elements form salts when they react with metals. The term ‘halogen’ means 'salt former'.
In addition to the discription given to norble gases in the question which is true, norble gases;
- are inert gases located on the right of the periodic table.
- have a full-set of valence electrons, so they're stable, unreactive
- are colorless, odorless and tasteless.
- have low melting and low boiling points.
- can be found in small amounts in the Earth's crust and the Earth's atmosphere.
