An atom contains three basic particles namely protons, neutrons and electrons . The nucleus of the atom contains protons and neutrons where protons are positively charged and neutrons are neutral. The electrons are located at the outermost regions called the electron shell.
What is the structure of atom answer?
Atoms consist of three basic particles: protons, electrons, and neutrons . The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge). The outermost regions of the atom are called electron shells and contain the electrons (negatively charged).
What is the structure of an atom?
An atom is a complex arrangement of negatively charged electrons arranged in defined shells about a positively charged nucleus . This nucleus contains most of the atom’s mass and is composed of protons and neutrons (except for common hydrogen which has only one proton).
What is an atom class 9th Ncert?
Answer: According to Thomson’s model of an atom. (i) An atom consists of a positively charged sphere and the electrons are embedded in it, (ii) The negative and positive charges are equal in magnitude. So the atom is electrically neutral . Question 2.
What is atom in science class 9?
The matter is made up of tiny particles called atoms. Atoms are further made of three fundamental particles or subatomic particles called electron, proton, and neutron . Protons and neutrons are almost of the same mass. The mass of the proton is approximately 2000 times as that of the electron.
What is atom with diagram?
Atomic diagrams were developed to explain the interaction of the elements of the Earth and space long before atoms could be observed. Nowadays, scientists can see particles that are smaller than an atom. ... An atom consists of three main parts: protons, neutrons, and electrons. Protons have a positive electrical charge.
What are the 4 types of atoms?
- Description. Atoms are made of tiny particles called protons, neutrons and electrons. ...
- Stable. Most atoms are stable. ...
- Isotopes. Every atom is a chemical element, like hydrogen, iron or chlorine. ...
- Radioactive. Some atoms have too many neutrons in the nucleus, which makes them unstable. ...
- Ions. ...
- Antimatter.
What are the 5 parts of an atom?
- Protons.
- Neutrons.
- electrons.
What is Valency class 9th?
It is the ability of an atom to gain or lose electron in order to achieve the noble gas configuration. It refers to the ability of an element to combine with other element. It is obtained by determining the number of electrons in the outermost shell (also called valence shell) of each atom of an element.
What is an element Class 9?
Element – It is the basic unit of matter, which cannot be broken down into substances by any way but can be combined to form new substances. It is a pure substance . It classifies into metals, non-metals, metalloids and noble gases. Example – Hydrogen, Carbon, Oxygen.
What is Mole class 9th?
The mole is the amount of substance that contains the same number of particles (atoms/ ions/ molecules/ formula units etc.) as there are atoms in exactly 12 g of carbon-12. • Mass of 1 mole of a substance is called its molar mass.
Why do we fall ill Class 9 notes?
It may be caused due to the attack of pathogens (virus, bacteria), lack of nutritious diet/balanced diet and lack of public health services . The disease which lasts for only a short period of time is called Acute Disease. For example: Influenza (Flu), Common cold, etc. For example: TB, Cancer, etc.
How do atoms exist?
Atoms exist in free states in the form of molecule . ... Molecules may be formed by the combination of atoms of two or more different elements. For example molecule of water. It is formed by the combination of two atoms of hydrogen and one atom of oxygen.
Who discovered atom Class 9?
Rutherford found that the atom is mostly an empty space where all its mass is concentrated in a tiny central nucleus. Thomson discovered electrons, which led him to further discovery of atomic theory.
What are electrons class 9th?
Electrons are subatomic particles that hold an elementary charge of magnitude -1 . The charge of an electron is equal in magnitude to the charge held by a proton (but has an opposite sign). Therefore, electrically neutral atoms/molecules must have an equal number of electrons and protons.
What is inside atom 9th class notes?
(i) Atom consists of predominantly empty space as most of α-particles passed through gold foil undeflected . (ii) Atom contains centrally placed positively charged nucleus (carrying positively charged particles), because few α-particles suffered deflected and very few i.e., one in 12000 bounced back.
