The mass of 1 mole of an element is its atomic weight on the Periodic Table in grams.
1g = 1000mg
The mass of 1 mole of Kr = 83.80g Kr
Convert mg Kr to g Kr.
398mg Kr x (1g/1000mg) = 0.398g Kr
Convert g Kr to mol Kr.
0.398g Kr x (1mol Kr/83.80g Kr) = 4.75x10-3mol Kr
Answer:
P = 58.52 atm
Explanation:
Given data:
Mass of sample = 32.0 g
Pressure of sample = ?
Volume of gas = 850 cm³
Temperature of gas = 30°C
Solution:
Number of moles of gas:
Number of moles = mass/molar mass
Number of moles = 32.0 g/ 16 g/mol
Number of moles = 2 mol
Pressure of gas:
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
30+273 = 303 K
850 cm³ × 1L /1000 cm³ = 0.85 L
by putting values,
P× 0.85 L = 2 mol × 0.0821 atm.L/ mol.K × 303 K
P = 49.75 atm.L/ 0.85 L
P = 58.52 atm
Answer: lithium- 3 protons, 3 electrons, 3 neutrons
Oxygen- nucleon no. 16, Atomic no. 8, 8 protons, overall charge (-2)
Sorry I don't the others. Hope this helps
It took 380,000 years for electrons to be trapped in orbits around nuclei, forming the first atoms.
These were mainly helium and hydrogen, which are still by far the most abundant elements in the universe. Present observations suggest that the first stars formed from clouds of gas around 150–200 million years after the Big Bang. Heavier atoms such as carbon, oxygen and iron, have since been continuously produced in the hearts of stars and catapulted throughout the universe in spectacular stellar explosions called supernovae.
