Oxygen in the air can cause sliced fruit to brown, a process called enzymic browning (an oxidation reaction). Phenols and the enzyme phenolase are found in the cells of the apple, and when these are exposed to oxygen in the air, for example through slicing, the oxygen causes a reaction.
A physical change is a change that the molecules of the article do not change so the answer is
a match chopping a piece of wood :))))
i hope this is helpful
have a nice day
Stress response and memory retention
Explanation:
During a stress response, many neurotransmitters or catecholamines like dopamine, adrenaline, noradrenaline, are released. The catecholamines are hormones which are released and acts as part of the body's fight-or-flight response.
Oversecretion of these catecholamines can hinder the long-term memory. However, these stress hormones do increase the short-term or the immediate recall memory. During an acute or an emotional stress response, the short-term, working, or the recognition memory becomes active.
The acute stress responses activates the sympathetic nervous system and areas of the brain like hippocampus and amygdala. These further improve the cognitive and sensory skills which improves the memory.
This also improves decision making skills to decide what is best during the fight-or-flight response.
Answer:
Natural factors of population change can't be swayed by humans. So for an example of a natural factor take an Earthquake. As of right now we can only predict when Earthquakes will. Inevitably some things will still get damaged and that just can't be helped. An Artificial factor for population change is something specifically made by humans. For an example take a genocide. If some guy decides he wants to go on a killing spree, well all I can say is that is Definitely not natural. Hope that helped.
