Can u guys check my 3 anwsers? *^* and tell me if i got them right?
you step on the scale and notice that you have lost five pounds. which of the following has changed?
a) only your mass changed.
b) only your weight changed. <
c) neither your mass nor weight changed.
d) both your mass and weight changed.
how could you increase the mass of a wooden block?
a) take it to jupiter where there is more gravity <
b) take it to the moon where there is less gravity
c) cut it in half
d) none of the above
if you went to the moon, how would your mass change relative to your mass on earth?
a) it would be the same on the moon as on earth
b) it would increase because of less gravity
c) it would decrease because of less gravity <
d) none of the above

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).