Answer:
- <em>To balance a chemical equation it may be necessary to adjust the </em><u>coefficients.</u>
Explanation:
The <em>coefficients</em> of a <em>chemical equation</em> are the numbers that you put in front of each reactant and product. They are used to balance the equation and comply with the law of mass conservation.
By adjusting the coefficients you obtain the relative amounts (moles) of each product and reactant, i.e. the mole ratios.
Here an example.
The first information is what is called a word equation. E.g. nitrogen and hydrogen react to form ammonia:
- Word equation: hydrogen + nitrogen → ammonia
- Skeleton equation: H₂ + N₂ → NH₃
This equation shows the chemical formulae but it is not balanced. The law of mass conservation is not observed.
So, in order to comply with the law of mass conservation you adjust the coefficients as follow.
- Balanced chemical equation: 3H₂ + N₂ → 2NH₃
As you see, it was necessary to modify the coefficients. Now the law of conservation of mass is observed and you get the mole ratios:
- 3 mol H₂ : 1 mol N₂ : 2 mol NH₃
Answer:
1s2 2s2 2p3
Explanation:
we know that the number of electrons in an atom is equal to number of protons. So the number of electrons here is 7.
Using Moller chart, the electronic configuration is writen by the electrons first enterring into 1s then into 2s after 2p. The s orbital accomodates maximum of 2 electrons.
∴ for atomic no. 7 nitrogen atom, electronic configuration is 1s2 2s2 2p3.
Answer: True
The formula of weight is w = mg, where m is the mass and g is the acceleration of gravity. If you want to calculate an object's weight, you need to know the two components: mass and gravity.
You only need to know the mass of the object because the acceleration of gravity is ALWAYS (assuming the object is on Earth) 9.8 m/s^2.
