Answer:
Eon-an indefinite and very long period of time, often a period exaggerated for humorous or rhetorical effect.
Era
Paleozoic-its end was marked by mass extinctions
mesozoic-between cenozoic and paleozoic
cenozoic- most recent era
period-a length of time
epoch-age
mass extinction- a huge die off of animals
landbridge- a strip of land connecting two large land masses
geographic isolation-island
Explanation:
Answer:
The correct answer is: X is nitrogen dioxide, and Y is a metal oxide
Explanation:
Combustion of compound of containing nitrogen and metal will give nitrogen dioxide and metal oxide as product. During combustion reaction a compound reacts with oxygen in order to yield oxides of elements present in the compound.
The general equation is given as:
Hence, the correct answer is :X is nitrogen dioxide, and Y is a metal oxide.
True
Explanation:
In the electron dot notation, the two dots on Be represents valence electrons in the s-sublevel.
The electron dot notation is also known as lewis dot structure.
This notation shows only the chemical symbol surrounded by dots to represent the valence electrons.
The dots are arranged at the four sides of the symbol in pairs called lone pairs. The unpaired ones are the odd electrons.
For Be, the structure is 1s² 2s²
The 2s sublevel is in the outermost/valence shell and it is made up of two electrons.
It is correct to say that the two dots on Be denotes the valence electrons in the s-sublevel.
learn more:
Lewis structure brainly.com/question/6215269
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The last set which is n=4 l=3 m=3 is a valid set
