<span>The correct answer is b. Option a is incorrect because these models can demonstrate scientific theories, but they don't prove scientific theories (you would need experiments for that). Option c is incorrect because the models aren't always representing something abstract (i.e. DNA is very real, just very small). Option d is incorrect because they don't precisely mimic something in nature, but instead help us visualize something in nature that is difficult to see or comprehend.</span>
Answer:
Brain cells are very sensitive to a lack of oxygen. Some brain cells start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause severe brain damage or death.
Explanation:
Other symptoms can include: hallucinations and delusions; increased agitation and confusion; depression and other mood disorders; personality changes, such as irritability and a reduced threshold for frustration; and an inability to focus or concentrate.
B.
Photosynthesis produces energy which is used during respiration to break down carbohydrates like starch into more usable forms like glucose
Answer:
B) lighting a match
Explanation:
a chemical change is a chemical reaction involving the rearrangement of atoms. While a physical change can often be reversed, a chemically change typically cannot.
Always remember, if something is being lit on fire then it is a chemical change, since fire breaks the bonds in between the atoms.
Freezing water is a physical change because it can be reversed and does not alter the substance, which is water. a change in state i always a physical change
tearing up a piece of paper is a physical change since nothing on a molecular level has changed. its still paper.
Dissolving sugar in water is a <em>homogenous mixture</em>, meaning that it looks uniform without, however it is still only sugar and water, so it is a physical change.
Oxygen, carbon dioxide and lipid
