What do these two changes have in common? using polish to remove tarnish from a silver spoon
salt and vinegar removing tarnish from a penny
Select all that apply.
Both are only physical changes.
Both are chemical changes.
Both are caused by heating.
Both are caused by cooling.

What happened in the 2000 election of al gore vs bush

When comparing the northern and southern hemisphere, why are the peak maximum and minimum values of insolation at different times of the year? specifically, why is the peak max of incoming solar radiation in june for the northern hemisphere, but in december for the southern hemisphere? pick the best, most complete answer. because of variations in the incident angle of solar radiation, due to the tilt of earth's axis, the northern hemisphere receives more direct solar radiation in june while the southern hemisphere receives less direct solar radiation. the reverse is true in december. because of earth's tilt, as the earth progresses in its revolution around the sun, the northern hemisphere is relatively closer to the sun in june while the southern hemisphere is relatively farther from the sun. the reverse is true in december. because of earth's elliptical orbit, the northern hemisphere is relatively closer to the sun in june/july while the southern hemisphere is relatively farther from the sun. the reverse is true in december. because of variations in the incident angle of solar radiation and the length of day, due to the tilt of earth's axis, the northern hemisphere receives more direct solar radiation and has longer daylight hours in june while the southern hemisphere receives less direct solar radiation and shorter daylight hours. the reverse is true in december.

Ascientist successfully predicts the outcome of an experiment. you watch carefully and know he didn't cheat. the scientist's success shows that: a) the scientist knows absolute truth about this experiment; success is not possible unless you know the truthb) the scientist was just lucky; no one ever knows what's going on, so successful predictions require luckc) the scientist may know the truth, or at least know something that is close to the truth, or the scientist may have gotten lucky this time; you can't be absolutely sured) the scientist really was cheating, even though you didn't see the cheating; no one can get things right, except by cheatinge) the scientist spent the night at a particular hotel chain and go a free breakfast, giving the scientist the ability to do amazing things