The correct answer is:
b: Heluim
Explanation:
The caffeine contains:
carbon , nitrogen , oxygen ,
hydrogen.
Caffeine is a primary nervous system energizer of the methylxanthine class. It is the world's most universally consumed psychoactive drug. Unlike many other psychoactive elements, it is fair and unlimited in nearly all parts of the world. Caffeine can be arranged as an alkaloid, a term used for substances originated as end results of nitrogen metabolism in some plants.
Only coniferous trees have thin, waxy, needle-like leaves that drop throughout the year and help to retain water.
<h3>What are coniferous trees?</h3>
Coniferous trees are evergreen trees that produce cones.
In addition, they produce waxy and needle-like leaves that help them conserve water by limiting the evapotranspiration rate as a result of reduced surface area.
Examples of conifers include pine trees and spruces.
More on conifers can be found here: brainly.com/question/23222416
Answer:
The possible valances can be determined by electron configuration and electron negativity
Good Luck even though this was asked 2 weeks ago
Explanation:
All atoms strive for stability. The optima electron configuration is the electron configuration of the VIII A family or inert gases.
Look at the electron configuration of the nonmetal and how many more electrons the nonmetal needs to achieve the stable electron configuration of the inert gases. Non metals tend to be negative in nature and gain electrons. ( They are oxidizing agents)
For example Florine atomic number 9 needs one more electron to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Flowrine has a valance of -1
Oxygen atomic number 8 needs two more electrons to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Oxygen has a valance charge of -2.
Non metals with a low electron negativity will lose electrons when reacting with another non metal that has a higher electron negativity. When the non metal forms an ion it is necessary to look at the electron structure to determine how many electrons the element can lose to gain stability.
For example Chlorine which is normally -1 like Florine when it combines with oxygen can be +1, +3, + 5 or +7. It can lose its one unpaired electron, or combinations of the unpaired electron and sets of the three pairs of electrons.
Explanation:
What's Dis Suppose To Mean ?
