Parantheses mean present of a subgroup or a group of polyatomic ions in a chemical reaction.
<u>Explanation:</u>
In a chemical reaction, sometimes, a compound may be composed of group of polyatomic ions with other ions. Some of the polyatomic ions are sulfate, carbonate, nitrate, hydroxide, bicarbonate, ammonia etc.
So these polyatomic ions are formed by combining two or more elements. Thus, if the number of polyatomic ions in a compound is more than one, then we use parathesis and write those polyatomic ions in it and write the number of polyatomic ions present in the compound as subscript of the parathesis.
For example, Fe₂(SO₄)₃
So here SO₄ is a polyatomic ion and in the compound 3 atoms of SO₄ is required to neutralize the compound and thus paranthesis is used. Thus, parantheses mean present of a subgroup or a group of polyatomic ions in a chemical reaction.
Answer
If the temperature is increased , the number of collision per second increases.
Explanation
Temperature is proportional to the average kinetic energy of a sample of a gas according to the equation PV=n R T. An increased in temperature , increases the kinetic energy of the gas particles which in turn rises the velocity of the gas particles hitting the walls of the container. The more the number of particles the higher the collision rate and greater the pressure as long as the volume of container and the temperature are constant.
A=24
N(n)=13
N(p)=A-N(n)
N(p)=24-13=11
²⁴Na - sodium
atomic number is 11
The right answer is ...
number 3
Scientists with different backgrounds and areas of expertise each contribute to the solution
