SCIENCE
CHEMISTRY
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
The smallest part of any substance which can exist on its own
|
|
|
Two or more atoms chemically joined together (can be the same or can be different)
|
|
|
A simple substance in which all the atoms are identical
|
|
|
Two or more different elements chemically joined together
|
Detailed explanation-1: -An atom is a particle of matter that uniquely defines a chemical element. An atom consists of a central nucleus that is surrounded by one or more negatively charged electrons. The nucleus is positively charged and contains one or more relatively heavy particles known as protons and neutrons.
Detailed explanation-2: -Electron – (symbol e-‐) a very tiny subatomic particle having a negative electric charge. Proton – (symbol p+) a tiny subatomic particle having a positive electric charge, located in the center of the atom (nucleus). The electron and proton have equal sized, but opposite polarity, electric charges.
Detailed explanation-3: -(A-tum) The smallest part of a substance that cannot be broken down chemically. Each atom has a nucleus (center) made up of protons (positive particles) and neutrons (particles with no charge). Electrons (negative particles) move around the nucleus.
Detailed explanation-4: -An atom is the basic building block of chemistry. It is the smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic properties of a chemical element.
Detailed explanation-5: -Answer: a. Atom: An atom is defined as the structural and functional unit of matter. It is the smallest particle of an element which retains its chemical identity in all the physical and chemical changes.