The model<span> of the </span>atom<span> has dramatically </span>changed<span> over many many years.We learn </span>atoms<span> make up different substances and are the smallest particles of matter. which can have subatomic particles that are very small portions of matter.at first scientist only thought there were electrons which are negatively charged.</span>
Answer:
An experiment is an investigation in which a hypothesis is scientifically tested. In an experiment, an independent variable (the cause) is manipulated and the dependent variable (the effect) is measured; any extraneous variables are controlled. An advantage is that experiments should be objective.
Explanation:
The ostrich runs 21 N then goes back by 25 S
The displacement is -4 S
21 - 25 = -4
Because matter cannot be created or destroyed
