H2-element
HCl-compound
Na-element
Al2O3-compound
H2O-compound
(2) Growing popularity of radio and motion pictures
<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!
Answer:
1 the number of electrons
Celsius scale is related to kelvin scale by the following equation,
⁰C = K-273
°C = K-273
So as here temperature is given in kelvin, so it can be converted into celsius as follows:
So 20 K = 20K-273 °C
= -253 °C .
So, the 20 K temperature equals to -253 °C.
So , -253 °C is equals to 20 K or 20 K temperature equals to -253 °C.