The correct option is C.
An atom can be either in the ground state or in an excited state. An atom is said to be in the ground state, if the total energy of its electron can not be lowered by moving one or more electrons into different orbitals. At the ground state, the electrons in the atom have the lowest energy possible and they are stable. On the other hand, an atom is said to be in an excited state, if the energy of its electrons can be lowered by transferring one or more electrons into different orbitals. An atom in an excited state has more energy and is less stable.
Atomic elements consist of a nucleus that contains protons and neutrons. Protons carry a positive charge whilst neutrons are electrically neutral. In light elements with an atomic number less than 20, the neutron to proton ratio is generally equal to 1:1. This changes for heavier elements since the Coulomb interaction between many protons gets stronger and demands more neutrons for the nucleus to remain stable.
Answer: De câte cărămizi am nevoie? Pentru un perete de cărămidă cu strat singular, înmulțiți lungimea peretelui cu înălțimea pentru a obține zona. Înmulțiți acea zonă cu 60 pentru a obține numărul de cărămizi de care ar trebui să aveți nevoie, apoi adăugați 10% pentru risipă. Acesta este răspunsul scurt și presupune dimensiuni „standard” de cărămidă și mortar.
The given reaction:
<span>ch3ch2cooh (aq) ↔ ch3ch2coo- (aq) + h+ (aq)
is called a reversible reaction.
This means that, the reaction does not reach an end point.
In this type of reactions, reactants react together to form products, while products combine together to form reactants.
So, the reaction proceeds in both direction forming both reactants and products.</span>
