Answer:a quantum absorption of energy
Explanation:
Bohr’s model explains the spectral lines .While the electron of the atom remains in the ground state, its energy is unchanged. When the atom absorbs one or more quanta of energy, the electron moves from the ground state orbit to an excited state and when the atom relaxes back to a lower energy state, it releases energy that is again equal to the difference in energy of the two orbits.
Answer: 318 K
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,

where,
= initial pressure of gas = 231 kPa
= final pressure of gas = 168 kPa
= initial volume of gas = 3.25 L
= final volume of gas = 4.35 L
= initial temperature of gas = 
= final temperature of gas = ?
Now put all the given values in the above equation, we get:


At 318 K of temperature will the same gas take up 4.35 liters of space and have a pressure of 168 kPa
Molar mass of oxygen gas:
O₂ = 16 * 2 = 32.0 g/mol
1 mole O₂ -------------- 32.0
9.05 mole O₂ ---------- ?
Mass = 9.05 * 32.0
Mass = 289.6 g of O₂
hope this helps!
Answer:
All living things are made up of cells.
cells are the basic unit of structure and function of ll living things.
All cells are come from other cells.
Explanation:
The cell theory is historic scientific theory and is universally accepted. This theory was given by Robert Hook in 1665. According to this theory all living things are made up cells.
Cell:
Cell is the smallest unit of life and it is building block of life.
This theory consist of following points:
All living things are made up of cells.
Cells are the basic unit of structure and function of ll living things.
All cells are come from other cells. Which means that cells are originated from pre-existing cells.
The other given options:
Cells comes from nonliving matter.
Cells make up most organisms bu not all.
These are two are not the postulate of cell theory because all living organisms are made of cells.
Answer:
<em>At equilibrium, the rate of the forward, and the reverse reactions are equal.</em>
Explanation:
In an equilibrium chemical reaction, the rate of forward reaction, is equal to the rate of reverse reaction. Note that the reactions does not cease at equilibrium, but rather, the reactants are converted to product, at the same rate at which the product is also being converted into the reactants in the reaction. When chemical equilibrium is reached, a careful calculation of the value of equilibrium constant is approximately equal to 1.
NB: If the value of equilibrium constant is far far greater than 1, then the reaction will favors more of the forward reaction, and if far far less than 1, the reaction will favor more of the reverse reaction.