Longer than visable light
Is this the full question?
<span>Heat that flows by conduction is the transfer of thermal energy between substances in contact. For this to happen, what must occur?
A) The two systems must be the same temperature.
B) The two systems must not be touching each another.
C) One system must have higher kinetic energy than the other system.
D) The thermal energy of one system must be the same as the thermal energy of the other system.</span>
Answer:
4.43L is final volume of the ballon
Explanation:
Avogadro's law of ideal gases states that <em>equal volumes of gases, at the same temperature and pressure, have the same number of molecules</em>.
The formula is:

Where V and n are volume and moles of the gas in initial and final conditions.
If the initial conditions are 0.0145 moles and 2.54L and final amount of moles is 0.0253moles, final volume is:

V₂ = <em>4.43L is final volume of the ballon</em>
Answer:
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
Explanation: Cause I'm smart like that!
The answer:
for the monoatomic <span>selenium ions
</span> -the ion charge of selenium is 2-, so the answer is [Se]2+
as for the monoatomic phosphorus ions
-the ion charge of phosphorus is 3-, so the answer is [P]3-