Answer:
There are 0,011 moles of hydrogen gas.
Explanation:
We use the ideal gas formula, with the constant R = 0.082 l atm / K mol. The STP conditions are : 1 atm pressure and 273 K temperature. Solve for the formula, n (number of moles):
PV=nRT ---> n= (PV)/(RT)
n= (1 atm x 0,25 L)/ (0,082 l atm/ K mol x 273 K)
<em>n= 0,011 mol</em>
Answer:
Atoms of each element contain a characteristic number of protons and electrons. The number of protons determines an element's atomic number and is used to distinguish one element from another.
Explanation:
Atomic Number = Number of protons
Mass Number = Number of protons + Number of neutrons
Isotopes are simply atoms of an element with the same number of protons and different number of neutrons.
First Isotope -- 238U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 238 - 92 = 146
Second Isotope -- 235U
Number of neutrons = Mass Number - Atomic Number
Number of neutrons = 235 - 92 = 143
