Answer: The correct option is 2.
Explanation: Polyatomic ions are defined as the ions in which two or more elements are covalently bonded to act as a single unit. They always carry some charge.
Examples of polyatomic ions are:
known as hydroxide ion,
known as sulfate ion
We are given a compound
having 2 ions which are
and
. these ions are named as sodium ions and hydrogen carbonate ions.
Therefore, the correct option is 2.
A producer gets it's matter from it's surroundings. E.g a plant will get minerals and water from the ground through it's roots for photosynthesis.
Plants can also produce food by using the sun's light for photolysis of the water molecules. (Basically splitting the H20 into Hydrogen and O2 (oxygen gas). They release oxygen back into the air and combine the Hydrogen ion with carbon dioxide that they obtained from the air to create sugar (glucose) which is basically chemical food for the plants. This is the summed up process of photosynthesis.
Answer:
The new volume is 1.62 L
Explanation:
Boyle's law says:
"The volume occupied by a given gas mass at constant temperature is inversely proportional to the pressure." It is expressed mathematically as:
Pressure * Volume = constant
o P * V = k
Charles's law is a law that says that when the amount of gas and pressure are kept constant, the ratio between volume and temperature will always have the same value:

Gay-Lussac's law indicates that when there is a constant volume, as the temperature increases, the gas pressure increases. And when the temperature is decreased, the gas pressure decreases. So this law indicates that the quotient between pressure and temperature is constant.
Gay-Lussac's law can be expressed mathematically as follows:

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law.

Having an initial state 1 and a final state 2 it is possible to say that:

Standard temperature and pressure (STP) indicate pressure conditions P = 1 atm and temperature T = 0 ° C = 273 ° K. Then:
- P1= 1 atm
- V1= 1.2 L
- T1= 273 °K
- P2= 0.80 atm
- V2= ?
- T2= 21°C= 294 °K
Replacing:

Solving:

V2= 1.62 L
<u><em>The new volume is 1.62 L</em></u>
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Answer:
The separation between layers of atoms in the crystal is 164.52 pm.
Explanation:
Formula used
(Bragg's law)
Where :
n = an order of reflection (integer)
= wavelength of the beam incident X-ray
d = spacing between the layer
θ = incident angle ( angle between ray and scatter plane)
We have :
λ = 157 pm
θ = 28.5°
n = 1
d = ?
(Bragg's law)

The separation between layers of atoms in the crystal is 164.52 pm.