Correct Answer:
B. 4
Explanation: The correct answer is 4.
The four commonly recognized primary states of matter are:
- Solid — definite shape and volume
- Liquid — definite volume, takes shape of container
- Gas — no definite shape or volume
- Plasma — ionized gas with free electrons and ions
Why the other options are incorrect:
- 3: This refers to the classical/traditional states (solid, liquid, gas), excluding plasma which is now considered a fundamental state.
- 5: While modern physics recognizes additional states like Bose-Einstein Condensate, they are not part of the "commonly recognized" primary states.
- 6: This includes exotic states (e.g., fermionic condensate) that are not taught at the basic level and are not "commonly recognized" in general science.
Therefore, 4 (solid, liquid, gas, plasma) is the correct answer for commonly recognized primary states of matter.