Answer:
density equals weigt divided by volume
Explanation:

Answer:
1) Ca: [Ar]4s²
2) Pm: [Xe]6s²4f⁵
Explanation:
1) Ca:
Its atomic number is 20. So it has 20 protons and 20 electrons.
Since it is in the row (period) 4 the noble gas before it is Ar, and the electron configuration is that of Argon whose atomic number is 18.
So, you have two more electrons (20 - 18 = 2) to distribute.
Those two electrons go the the orbital 4s.
Finally, the electron configuration is [Ar] 4s².
2) Pm
The atomic number of Pm is 61, so it has 61 protons and 61 electrons.
Pm is in the row (period) 6. So, the noble gas before Pm is Xe.
The atomic number of Xe is 54.
Therefore, you have to distribute 61 - 54 = 7 electrons on the orbitals 6s and 4f.
The resultant distribution for Pm is: [Xe]6s² 4f⁵.
Answer:
0.675 atm
513 Torr
Explanation:
Given is that, the atmospheric pressure on the surface of Venus is
6.84 X 10⁴ Pa.
1 atm (atmospheric pressure) is equal to 101325 pascal (Pa).
To convert divide the pressure value by 101325.
Pressure in atm = 
= 0.675055 atm
Rounding it off to 3 significant digits: 0.675 atm
Now, one Torr is 133.322 Pa. For conversion, divide the pressure value by 133.322.
Pressure in Torr = 
=513.04219 Torr
Rounding it off to 3 significant digits: 513 Torr
The wording of your question doesn't quite make sense, but a mole of an element has the same mass in grams as a single atom of that element has in amu. The mole is defined as 6.02 x10^22 things, whether they be atoms or molecules or even moles! 6.02x10^22 atoms of carbon has a mass of 12.01 g, and a single atom of carbon has a mass of 12.01 amu. Hope this helps!
Answer:
Gas – In a gas, particles are in continual straight-line motion. The kinetic energy of the molecule is greater than the attractive force between them, thus they are much farther apart and move freely of each other. In most cases, there are essentially no attractive forces between particles.
Explanation:hopes this helps:)