All aspiring BDS and MBBS candidates in India must pass the National Eligibility Entrance Test. The NTA (National Testing Agency) conducts the test. NEET’s latest exam pattern includes 200 multiple-choice questions that each carry four marks. These questions are based on 11th and 12th-standard syllabi in Physics, Chemistry, and Biology. Candidates must answer 180 questions out of 200.
It’s quite simple, right? General candidates must score at least 50% in each of these subjects to pass the exam. To pass the exam, you must score at least 50% in Biology and Chemistry. To pass the exam, you must be proficient in all subjects.
What is an Atom?
An atom is the smallest unit of an element. All the chemical properties of an element are retained in an atom. When atoms from an element combine, they form molecules. These molecules interact to create liquids, gasses, and solids. Water, for example, is made up of hydrogen and oxygen atoms. Water is formed when the atoms of Hydrogen & Oxygen combine.
What are Atomic Particles ()?
An atom is composed of three particles: protons, electrons and neutrons. The nucleus is the centre of an atom. It is home to the neutrons, which are protons that have a negative charge and are not charged.
The electron shells in the outermost regions of an atom contain subatomic particles called electrons. The electrons are positively charged particles. The number and arrangement of these basic particles will determine the properties of an atom.
This is why hydrogen (H) atoms are a good example. One electron and one proton are all found in Hydrogen atoms. These particles can be used to determine the Hydrogen atom’s mass and atomic numbers.
- What’s an Atomic Number?
A neutral element would have electrons and protons equal in number. The atomic number (Z), of an element, is determined by the number of protons. This atomic number distinguishes between elements. This is illustrated by carbon. Carbon has an atomic number of 6. This means that one carbon atom contains 6 protons.
To form isotopes, however, the number and composition of neutrons can vary. These are atoms that have different amounts of neutrons but belong to the same element. The number of electrons in an element’s atoms for forming ions, also known as charged atoms, might be different. Take Fe (Iron) as an example. It has its neutral state, and 3 and 2 ionic states.
- What’s Atomic Mass Number?
The sum of protons and neutrons in an element’s mass number (A), is called the element’s element’s mass number. The mass of electrons in an element is not taken into account when calculating its atomic mass number. This approximate atomic weight is used to calculate the number of neutrons. To do this, subtract the proton number from atomic number. One AMU (atomic matter unit) is made up of protons and neutrons. The isotopes can have different mass numbers, but they will all have the same atomic number.
What is an Atomic Structure?
An atom is composed of a nucleus, electrons and a nucleus. This is how an element’s structure of atoms refers to the arrangement of electrons and nucleus. The atomic structure also includes protons, electrons, neutrons.
A nucleus is composed of protons and neutrons. The nucleus is then surrounded by electrons. An atom’s atomic number is determined by the number of protons in its nucleus. Neutral atoms contain equal amounts of protons and electrons. For greater stability, some elements’ atoms can gain or lose electrons. An ion is a newly charged entity.
Each atom structure has its own electrons and protons. This is why elements have unique characteristics.
What is the Atomic Model?
Numerous scientists have tried to show the atomic structure using atomic models since the 18th century. John Dalton, Ernest Rutherford and J. J. Thomson are the most prominent contributors to this field. Each model provided by these scientists has its merits and detractors.
All models played a pivotal role in the development of the atomic model that we see today, but John Dalton Atomic Theory is the best. So, let us read about it.
Atomic Theory by John Dalton
John Dalton, an English chemist, suggested that all matter is made up of indestructible and irreversible atoms. He also claimed that all elements have the same atoms. But, different elements’ atoms have different masses and sizes.
According to the atomic theory by Dalton, chemical reactions are atom rearrangement to create products. He concluded that atoms were the small particles of an element responsible in chemical reactions.
These are the results of Dalton’s theory.
- Atoms are the smallest unit in matter and all matter is made up of them.
- A single type of atom would be found in an element.
- Atoms are indestructible.
- The constant mass of an atom is the same across all elements.
- Atoms can’t be destroyed or made, but they can be transformed into another form.
- In a chemical reaction, the arrangement of atoms is changed.
The Laws of Chemical Reactions were successfully described by Dalton’s Atomic Theory. These include Law of Reciprocal Proportions and Law of Multiple Proportions.
NEET applicants must have a solid understanding of the structure and function of atoms. It is one of the most important concepts in chemistry. Understanding atomic structure is also necessary to understand other concepts in chemistry, such as General Organic Chemistry, Chemical Bonding and others, so that you can pass NEET.