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.
Unlike nuclear reactions, nuclear reactions are not affected by changes in temperature,
pressure, of the presence of catalysts. Also nuclear reactions of given radioisotope cannot be slowed down, speeded up, or stopped.
Answer:
when the forward and reverse reactions occur at equal rates.
chemical reaction is in equilibrium when the concentrations of reactants and products are constant - their ratio does not vary.
Answer:
Explanation: This reaction is called a synthesis reaction. This is because a synthesis reaction is when two or more reactants combine/react together to form a single product. The two reactants carbon (C) and oxygen (O2) reacted together to form one single product: carbon dioxide (CO2)
Answer:
m = 50.74 kg
Explanation:
We have,
Initial temperature of water is 20 degrees Celsius
Final temperature of water is 46.6 degrees Celsius
Heat absorbed is 5650 J
It is required to find the mass of the sample. The heat absorbed is given by the formula ad follows :
c is specific heat of water, c = 4.186 J/g°C
So,
So, the mass of the sample is 50.74 kg.
