Answer:
the Rhyniognatha hirsti
Explanation:
at age 400 million years old
Answer:
Examples of radioactive isotopes include carbon-14, tritium (hydrogen-3), chlorine-36, uranium-235, and uranium-238.
Explanation:
Mole = 0.5 = n/NA
n = no. of molecule
NA = avogadro number = 6.023x 10^23
so
N/NA = 0.5
N = 0.5 x 6.023 x 10^23
N = 3.0115 x 10^23
Answer:
2.24dm³
Explanation:
Given parameters:
Mass of He = 40g
Unknown:
Volume of Helium = ?
Solution:
To solve this problem, we convert the given mass to number of moles.
Number of moles =
molar mass of He = 4g/mol
Number of moles =
= 0.1mole
So;
1 mole of gas at rtp occupies a volume of 22.4dm³
0.1 mole of He will occupy a volume of 0.1 x 22.4 = 2.24dm³
Answer:
wattter
Explanation: H20 jk lma++ooo