The mass number is the number of protons and neutrons added together. Electrons are not counted as part of the mass because while protons and neutrons weigh the same, Electrons weigh virtually nothing compared to them. As far as I can tell, there is no stable atom with a mass of 8.

Covalent.

CH3-Cl = chloromethane

CH2-Cl2 = di-chloromethane

CH-Cl3 - tri-chloromethane

CCl4 = tetrachloromethane.

All the bonds are covalent. However, because of chlorines strong electronegativity , the electrons in the C-Cl bond polarise towards the chlorine.

Nitrogen is a NON-metallic gas. It does not IONISE readily.

However, it has ELECTRON AFFINITY. This means that it will gain electrons to form a negative ion (ANion)

When an atom of nitrogen gains electrons it is shown as 'N^(3-).

The charge on a proton is deemed to be POSITIVE.

NB

The charge on an electron is deemed to be NEGATIVE ( opposite charge)

The charge on a neutron is deemed to be ZERO(NO CHARGE).

the size of atom doesn't decrease regularly due to the reason of lanthanide contraction .there is slightly increase or or almost no increase in atomic radius from 5th to 6th period in transition metal .

Electrically charged atoms are collectively called ION.S.

Once an atom becomes elecgrically charged it is no longer an atom , but an ION.

A positively charged ion is called a CATION e.g. Na^(+)

A negatively charged ion is called an ANION e.g. Cl^(-) .

A molecule of hydrogen, also known as molecular hydrogen, is composed of two atoms of hydrogen. This diatomic molecule is represented by the chemical formula H₂, indicating the two hydrogen atoms are bonded together.

Chlorine gas is a diatomic molecule, Cl2. Two atoms per molecule. A mole contains Avogadro's Number of particles, that being (approximately) 6.02 x 1023. Hence, the number of atoms in one mole of chlorine gas is twice Avogadro's Number, or approximately 1.204 x 1024.

A double bond. Each atom that can share valence electrons has a bonding capacity corresponding to the number of covalent bonds the atom can form. When the bonds form, they give the atom a full complement of electrons in the valence shell. The bonding capacity of oxygen, for example, is 2. ( O=O )

There are 3 atoms in one CO2. So there will be 12 atoms in 4CO2.

The ATOMIC NUMBER (Z) gives the position of an element in the Periodic Table.

It also indicates the number of protons and electrons in an atom of a given element.

Taking two examples;-

Z = 1 ; Hydrogen ; No. of protons = 1, No of electrons = 1

Z = 6 ; Carbon ; No. of protons = 6, No of electrons = 6

TNT is 'tri-nitrotoluene'.

This is a benzene ring of 6 carbons.

On Carbon No. 1 the is a CH3 group

On carbons No's. 2,4 & 6 there are three NO2 group .

The remaining two carbons viz, 3 & 5 , have an hydrogen attached.

So the elements present are Carbon, Hydrogen, Nitrogen and Oxygen.

The formula is C7H5N3O6

The force that keeps protons and neutrons bound together within the atomic nucleus is called the "strong nuclear force" or "strong interaction." The strong nuclear force is one of the fundamental forces of nature and is responsible for holding the nucleus together despite the electric repulsion between positively charged protons.

The strong nuclear force is mediated by particles called "gluons." Gluons are the carriers of the strong force and interact with quarks, which are the elementary particles that make up protons and neutrons.

The strong force is unique in that it becomes stronger as particles get closer together, thus overcoming the electromagnetic repulsion between protons.

The strong force is crucial for the stability of atomic nuclei and plays a significant role in nuclear physics. It is responsible for binding protons and neutrons together to form the nucleus and is also involved in processes such as nuclear reactions and nuclear energy production.

There are 10 atoms in two nitric acid molecules. Namely they are two hydrogen atoms, two nitrogen atoms and six oxygen atoms.

It does NOT form molecules.

When AlCl3 'breakdown ' it form the IONS Al^(3+) & 3 Cl^(-)

AlCl3(s) IS a molecule.

Americium-243 might undergo alpha decay to become neptunium-239, and here is that equation:

95243Am => 93239Np + 24He++

The americium-243 has undergone transmutation to become neptunium-239, and the alpha particle, which is a helium-4 nucleus, can be seen on the tail end of the equation.

Adenosine is a combination of the molecule adenine and the sugar ribose. It is a nucleoside that plays a key role in various biochemical processes in the body, such as energy transfer and signaling pathways.

The littuns obeyed the summon of the conch in "Lord of the Flies" because it represented order and civilization in their society. They viewed the conch as a symbol of authority and democracy, so they followed its call as a way to maintain structure and organization among the boys on the island.

It is only the protons that matter in classifying the element. Sulfur has 16 protons (An atomic number of 16).

An ATOM.

The sub-atomic particles are

Protons, Neutrons. and Electrons.

The protons and neutrons are collectively named 'nucleons, because they form the nucleus of an atom.

The electrons are in energy shells around the nucleus.

For the same element the number of protons and electrons remains unaltered.

Howerm for that same element the number of neutrons can vary., leading to different atomic masses.

Taking hydrogen as an example. It has three isotopes.

#1 ; protium ; 1 proton , 0 neutrons (Atomic Mass ; 1 + 0 = 1 )

#2 ; deuterium ; 1 proton , 1 neutron ( Atomic mass ; 1 + 1 = 2)

#3 ; tritium ; 1 proton, 2 neutrons ( Atomic Mass ; 1 + 2 = 3)

Notice for each isotope of hydrogen there is only ONE proton. However, for each different isotope of hydrogen there is a different number of neutrons.

The Atomic Mass is the sum of the protons and neutrons).

#4 ; Helium(He) ; 2 protons, 2 neutrons ( atomic mass 2 + 2 = 4 ).

For comparison helium has 2(TWO) protons and 2 neutrons, but it is an entirely different element, because it has a different number of protons.

YES!!!

The difinitive answer is ' Isotopes of an element have a DIFFERENT number of neutrons'.

Takinf an example. The element Hydrogen .

It has three isotopes. They are: -

#1 ; protium ; 1 proton , 0 neutrons, 1 electron ; Atomic mass '1'

#2 ; deuterium ; 1 proton , 1 neutron , 1 electron ; Atomic mass '2'

#3 ; tritium ; 1 proton 2 neutrons 1 electron. 'Atomic mass '3',

Carbon also has three isotopes biz.,

# 1 ; Carbon-12 ; 6 protons, 6 neutroins, 6 electrons ;Atomic mass '12'

#2 ; Carbon-13 ; 6 protons, 7 neutroins, 6 electrons ; Atomic mass ''13'

#3 ; Carbon-14 ; 6 protons, 8 neutroins, 6 electrons ; Atomic mass '14'.

Notice in each case the number of neutrons changes, the number of protons remains the same, otherwise it is a different element. The Atomic mass is the sum of the protons and neutrons.

NNB Every element has isotopes.

NNNN Do not confuse 'Isotopes' with 'Allotropes'. Allotropes are elements exhibiting a different physical form/appearance.

Protons, Neutrons, and Electrons.

Protons and Neutrons are found in the nucleus of an atom, and collectively called 'nucleons'.

Electrons are found outside the nucleus, in energy shells.

The iron atom loses two(2) electrons to be come the Iron ION.

Fe = Fe^(2+) + 2e^-

NB An atom , when it becomes a charged spacied , is no longer an atom , but an ION.

Positively charged ions are CATIONS

Negatively charged ions are ANIONS.