<span>A fast moving stream of air has a lower air pressure than a
slower air stream. As the stream of air moved over the
top of the paper, the air pressure over the paper dropped. The
air pressure underneath the paper stayed the same. The
greater air pressure underneath lifted the paper strip and it
rose. The idea that a moving air stream has lower air pressure
than air that is not moving is called “Bernoulli’s Principle”.
</span>The
force of the moving air underneath the balloon was enough to
hold it up. The weight added by the paper clip prevents
the balloon from going too high. But that is only part
of the story. The balloon stays inside the moving stream
of air because the pressure inside is the air stream is lower
than the still air around it. As the balloon moves toward the
still air outside of the air stream, the higher pressure of
the still air forces the balloon back into the lower pressure
of the air stream. Bernoulli’s Principle at work again!
Blank 1: polar
The difference in electronegativity between N and H causes electrons to preferentially orbit N, making the bond polar.
Blank 2: trigonal pyramidal
There are four “things” attached to N - 3 H’s and 1 lone pair of electrons. The four things together are arranged into a tetrahedral formation. However, the lone pairs don’t actually contribute to the shape of the molecule per se; it’s only the actual atoms that do. The lone pair creates a bit of repulsion that pushes the 3 H’s down, creating a trigonal pyramidal shape (as opposed to a trigonal planar one).
Blank 3: polar
The molecule as a whole is also polar because the “things” around it, though arranged in a tetrahedral pattern, are not all the same. The side of the molecule with the lone pair is slightly negative, while the side with the 3 H’s is slightly positive due to the differences in electronegativity described above.
Well the answer to number 1 is definitely B
number 2 is B
number 3 is D
Number 4 is C
Hope this helps:)
Answer:
The word "Halloween" comes from All Hallows' Eve and means "hallowed evening."
Halloween's origins can be traced back to the ancient Celtic festival known as Samhain, which was held on November 1 in contemporary calendars. It was believed that on that day, the souls of the dead returned to their homes, so people dressed in costumes and lit bonfires to ward off spirits.
Explanation:
22 is a
23 is d
24 is c
I believe the answers are correct.
