Diagram A shows the Lewis structure (LS) of CH_2O. The formal charge on each atom is zero.
To get the formal charge (FC) on the atoms, cut each bond in half, as in <em>Diagram B</em>. Each atom gets the electrons on its side of the cut.
Formal charge = valence electrons in isolated atom - electrons on bonded atom
FC = VE - BE
<em>On O:
</em>
VE = 6
BE = 2 lone pairs 2 + 2 bonding electrons = 4 + 2 = 6
FC = 6 – 6 = 0.
<em>On H:
</em>
VE = 1
BE = 1 bonding electron
FC = 1 – 1 = 0
<em>On C:
</em>
VE = 4
BE = 1 in each single bond + 2 in the double bond = 2 + 2 = 4
FC = 4 - 4 = 0
Answer:
option A = In first diagram red arrow pointed towards the greatest concentration of atomic mass.
Explanation:
Every atom consist of nucleus or a positive center. The protons and neutrons are present with in the nucleus while electrons are present out side the nucleus. All these three subatomic particles construct an atom. The number of protons or number of electrons are the atomic number of an atom while the number of protons and number of neutrons are the mass number of an atom. A neutral atom have equal number of protons and electrons. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other.
Nitrogen consist of seven protons and seven neutrons present with in nucleus and seven electrons are present out side the nucleus.
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Neutron and proton:
The neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
Explanation:
1. subatomic particles.
2.proton, electron and neutron
3.The atomic mass of an element is actually the sum of the MASSES of protons and neutrons in AN atom of that element
4.An element's atomic number is equal to the number of protons in the nuclei of any of its atoms
5. Number of Protons = Atomic Number
Number of Electrons = Number of Protons = Atomic Number
Number of Neutrons = Mass Number - Atomic Number
For krypton:
Number of Protons = Atomic Number = 36
Number of Electrons = Number of Protons = Atomic Number = 36
Number of Neutrons = Mass Number - Atomic Number = 84 - 36 = 48
6. electron, lightest stable subatomic particle known. It carries a negative charge of 1.602176634 × 10−19 coulomb, which is considered the basic unit of electric charge. The rest mass of the electron is 9.1093837015 × 10−31 kg
7.The center of the atom is called a nucleus
8. Negatively charged particles are found in multiple layers outside the nucleus of the atom. These particles are called electrons, and they orbit in various energy levels around the atom's nucleus.
9. A charged particle is also called an ion
Answer:
Dmitry Mendeleev
Explanation:
Around 1869 a Russian scientist, Dmitry Mendeleev formed what is now known as the periodic table or chart. The Mendeleevian periodic table was based on the atomic weights of elements using the periodic law. The periodic law states that "chemical properties of elements are a periodic function of their atomic weights".
The modern periodic table was re-stated by Henry Moseley in the 1900s. He changed the basis of the periodic law to atomic masses.
Fireworks changes chemical energy into light energy
