Here’s a detailed set of notes on the topic of “Atoms and Molecules” for Class
9 science:
**Atoms and Molecules**
**Introduction:**
- Everything around us, including living and non-living things, is made up of
matter.
- Matter is made up of small particles called atoms and molecules.
**Atoms:**
- An atom is the smallest particle of an element that retains the properties of
that element.
- Atoms are made up of subatomic particles: protons, neutrons, and
electrons.
- Protons and neutrons are located in the nucleus of the atom, while
electrons orbit the nucleus in shells or energy levels.
**Atomic Structure:**
- The nucleus of an atom contains protons and neutrons, which are positively
charged and neutral particles, respectively.
- Electrons, which are negatively charged, orbit the nucleus in different
energy levels or shells.
- The number of protons in an atom determines its atomic number, which
defines the element.
- The total number of protons and neutrons in an atom is called its mass
number.
9 science:
**Atoms and Molecules**
**Introduction:**
- Everything around us, including living and non-living things, is made up of
matter.
- Matter is made up of small particles called atoms and molecules.
**Atoms:**
- An atom is the smallest particle of an element that retains the properties of
that element.
- Atoms are made up of subatomic particles: protons, neutrons, and
electrons.
- Protons and neutrons are located in the nucleus of the atom, while
electrons orbit the nucleus in shells or energy levels.
**Atomic Structure:**
- The nucleus of an atom contains protons and neutrons, which are positively
charged and neutral particles, respectively.
- Electrons, which are negatively charged, orbit the nucleus in different
energy levels or shells.
- The number of protons in an atom determines its atomic number, which
defines the element.
- The total number of protons and neutrons in an atom is called its mass
number.
