Answer:
O(Oxygen)
Explanation:
2+2+4=8
And the eighth element of the periodic table is Oxygen
<span> Vertical height of longest escalator in free world = 58.8 sin 32.4 = 31. 5 m
Karen's mass = 54.6 kg
Work done on Karen = mgh = 54.6(9.81)(31.5) = 1.69e4 J = 16.9 KJ ANS </span>
The mass of the atom is equal to the sum of the number of protons and the number of neutrons. In a neutral atom, the number of protons is equal to the number of electrons. The atomic number meanwhile of an atom is equal to the number of protons of the atom.
Answer:
2 Atm; 2.016 g
Explanation:
Changing the volume without changing the temperature or mass only changes the pressure. Volume and pressure are inversely proportional so halving the volume will double the pressure.
P = 1 Atm, T = 0 °C are "standard" temperature and pressure (STP). The volume of 1 mole of gas is 22.4 L under these conditions. That means the amount of hydrogen gas in the cylinder is 1 mole, so has a mass of 2.016 g.
After the volume reduction, the pressure is 2 Atm, and the mass remains 2.016 g.
I believe it might be A, hope this helps!