<h3>→soft and reactive metals. </h3>
Explanation:
<h3>Alkali metals are soft and reactive metals. They react vigorously with water and become more reactive. And other hand halogens are reactive non metals. ... Halogens can be solid, liquid, gaseous at room temperature and the melting point increase when they get bigger.</h3>
<h2>#CAREYINGTOLEARN❤️</h2>
1) If the volume of a container is increased, the temperature increases. 2) If the volume of a container is decreased, the temperature decreases. This means that the volume of a gas is directly proportional to its temperature. ... If the amount of gas in a container is increased, the volume increases.
Grinding as it’s a physical not chemical change :)
Answer:
17.6510 L
Explanation:
First we should get the number of moles of helium here by Boyle's law
PV=nRT
P=750/760= 0.9868 atm
T=25+273=298 kelvin
R= 0.08206
V= 20L
so
n=PV/RT
n=0.9868×20/0.08206×298
n=0.80707 mol
Then use the same law
V=0.80707×0.08206×263/0.9869=
17.6510L
SO THE VOLUME WILL BE 17.6510 L
Y is Po-218.
<h3>Explanation </h3>
Here's the symbol of a particle in a nuclear reaction. 
.
A stands for mass number. Z stands for atomic number. Both numbers shall conserve in a nuclear reaction.
- The mass number on the left hand side is 222.
- The two mass numbers on the right hand side add up to A + 4.
- 222 = A + 4.
- A = 218
So is the case for the atomic number. Try figure out the atomic number of Y using the same approach.
- The atomic number on the left hand side is 86.
- The two atomic number on the right hand side add up to __ + __.
- 86 = __ + __.
- Z = 84.
What element is Y? The atomic number of Y is 84. Refer to a periodic table. Element 84 corresponds to Po (polonium). Y is Polonium-218. The symbol of Y should be written as 
. Hence the equation:
.
