Answer To: Activity Sheet-2 Minerals - Lecture XXXXXXXXXXpoints It’s all about relationships. As you prepare...
Nikhil answered on Sep 23 2021
1. Basics parts of Atom -
An atom is basically consisting of 4 parts, namely electron, proton, neutron and nucleus. An electron is a negatively charged particle which is located in the circular rings, called Orbits, spinning around the nucleus.
The protons are positively charged particles and neutrons are neutral in charge. Both can be found at the centre of the atom, called nucleus.
All the electrons of an atom are bounded around the nucleus of the atom. The nucleus has typically similar number of protons and neutrons, which are collectively known as Nucleons.
Atomic Number -
The atomic number of an atom is defined as the number protons present in the nucleus of the atom. The identity of the atom is defined by the number of protons present in the atom. For ex. If an element has 6 protons then the element is carbon atom, no matter how many neutrons are there in the nucleus.
Atomic Mass -
It’s the mass of an atom in a chemical element. It is equivalent to total number of protons and neutrons present in the atom and is expressed in Atomic Mass Unit, denoted by “u”.
1 amu = 1/12th of 1 atom of C-12
For ex. In an atom of Nitrogen, there are 7 protons and 7 neutrons present in its nucleus. So , the Atomic number of N = 7,
and, Atomic mass = 7+7 = 14 u.
Subatomic particles are negatively and positively charged because atoms can lose or gain electrons. When they do this, they form ions. The one which loses electron becomes cation (positively charged) and the one which gains electrons becomes anion (negatively charged).
2. In an electrically balanced atom, the number of protons and the number of electrons is same, i.e, number of protons = number of electrons. As the protons are electrically positive and electrons are electrically negative, so to make an atom electrically neutral, they should be same in number.
Atomic number = AN, Atomic Mass = AM
Atomic number is the total number of Protons present in the nucleus of an atom. And to make an atom electrically neutral, the number of Electrons present in the atom is also same.
Atomic Mass is the sum of total number of protons and neutrons present in the nucleus of the atom.
1. Number of Electrons = 16, Number of Neutrons = 7, and atom is electrically balanced.
So, Number of Protons = Number of Electrons, since its electrically balanced.
Therefore, Number of Protons = 16
AN = 16,
AM = AN + Number of Neutrons
= 16+7
= 23u
2. AM = 47, AN = 24, Electrically balanced
So, Number of Neutrons = AM – AN
= 47 – 24
= 23
& number of electrons = AN
= 24
3. 25 Protons, 12 Neutrons, electrically balanced
So, AM = Number of Protons + Number of Neutrons
= 25 + 12
= 37 u
AN = Number of Protons
= 25
& number of electrons = AN
= 25
3. Chemical Element –
A chemical element or an element, is defined as a material or substance consisting of only one type of atom, which can’t be broken down or changed into another substance by simple chemical reactions. They’re considered as the building block of matter. There are total of 118 elements that have been identified and out of which 94 are naturally occurring elements and rest 24 are synthetic elements.
1. Relation between atomic number and chemical element –
The elements are made up of only one type atom, so these atoms would also have electrons, protons and neutrons in it. Since, the total number of protons in the nucleus is atomic number of the atom/element.
So, it’s the defining property of the element and so is referred as atomic number.
2. Minerals are naturally occurring inorganic solid substances made up of chemical elements and each mineral has its own chemical composition and crystal structure. They’ve a set of physical properties that can be used to identify them. For example, Quartz is a naturally occurring solid and inorganic mineral. Its structure can be seen in its crystal form. Chemical composition is SiO2, Silicon and Oxygen. It’s made up of more than one element.
Whereas, there are some naturally occurring minerals such as Gold, which is also an element.
So, we can say/conclude that elements can be considered as minerals but minerals cannot be considered as elements. Because some minerals are made up of more than one element which contradicts the main definition of element.
4. Yes, same element can occur as solid, liquid and gas such as Carbon, Sulphur etc. Carbon can exist as Graphite, Diamond, some other amorphous solid carbon, liquid CO2 (used in refrigeration, fire suppression systems), CO2 gas. Sulphur also has many solid phases as well as liquid and gaseous phase. These different phases of same elements occur at different temperature, pressure and conditions.
All substances/elements can be solid, liquid or gas at some temperature and pressure. But most of the elements are solid/metallic in nature at normal room temperature and pressure. It’s because they’ve extended metallic bonding conditions hence have higher melting points. Whereas there are some elements which exist as liquid at room temperature and pressure, for example, Mercury, Gallium.
On the other hand, there are some elements which exists as molecules such as Cl2, O2, Br2 etc. These are in gaseous state (Cl2, O2) & liquid state (Br2) under normal conditions.
There are also few molecular elements that are solids under normal conditions. They’re Phosphorous (P4) and Iodine (I2).
Hence, most of the elements are solid under normal conditions...