It can be a compound or a single element. An element is a pure substance that cannot be separated into simpler substances by chemical or physical means. There are about 117 elements, but carbon, hydrogen, nitrogen and oxygen are only a few that make up the largest portion of Earth.
hopefully that helps
answer: focus or hypocenter
enplanation: when energy release at the focus, seismic waves travel outward from that point in all directions.
Answer:
half-life = 3.8 days
total time of decay = 15.2 days
initial amount = 100. g
number of half-lives past: 15.2/3.8 = 4 half-lives
4 half-lives = 1/16 remains
100. g x 1/16 = 6.25 g
The question is missing the graphics required to answer which I have attached as an image.
There are four different representations of the orientation of water molecules around chloride anion. Let's first analyze the water molecule.
We have H-O-H as the structure of water. The oxygen atom is more electronegative than the hydrogen atoms, which results in a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom.
The chloride anion is a negative charge. Therefore, the water molecules should orient themselves with the hydrogen atoms facing the chlorine atom as the partial positive charge on the hydrogen atoms will be attracted to the negative charge of the chlorine atom.
The correct representation is shown in graph 3 which shows all hydrogen atoms facing the chlorine anion.
Answer is: a mixture.
Crude oil is mixture (solution) consist of several different hydrocarbons (alkanes, alkenes...). This hydroalkanes can be separated from mixture (crude oil) using distilation (usually fractional distillation), because they have different boiling points.
Proportion of hydrocarbons is diiferent in varios parts of the world.
Solution is homogeneous mixture composed of two or more substances.