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.
Answer:
2. All the naturally occurring isotopes of Mg.
Explanation:
You want to know the atomic mass of the magnesium you use in the lab. That’s “natural” magnesium. So, you must use the weighted average of all the naturally occurring isotopes in natural Mg.
1. and 3. are <em>wrong</em>. You won’t get the correct mass for natural Mg if you use only the artificial isotopes for your calculation.
4. is <em>wrong</em>. You must use all the naturally occurring isotopes. The two most abundant isotopes of Mg account for only 90 % of the atoms. If you ignore the other 10 %, your calculation will be wrong.
I believe it is C, as helium is one of the lightest noble gases making the particles move faster.
Answer:
100
Explanation:
M = mass/ number of mole
M = 3.5 g/0.035 mol = 100 g/mol - molar mass
Answer:
increase in solvent temperature will increase the solubility of solid particle but decreases the solubility of gas particle.
Explanation:
In solid particle when temperature increases its help to break apart the solid particle and increase in kinetic energy of solvent results in increase in solubility of solid particles in solvent.
but in gas solute, increase in temperature of solvent causes the increase in motion of gas molecules means increase in kinetic energy of molecules in the gas which results in breakage of inter molecular bonds and removal of the molecules from the heated solution.
