Questions and Answers
Which subatomic particle has a negative charge?
Electron
What is the chemical symbol for sodium?
Na
What is the formula for calculating the density of a substance?
$\frac{mass}{volume}$
Which of the following is an example of a chemical change?
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Which of the following best describes a radical in chemistry?
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What is the role of acids and bases in chemical reactions?
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What is the fundamental difference between an atom and a molecule?
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Study Notes
Subatomic Particles
- Electrons are the subatomic particles that have a negative charge.
Sodium
- The chemical symbol for sodium is Na.
Density Calculation
- Density can be calculated using the formula: Density = Mass/Volume.
Chemical Change
- A chemical change involves the transformation of substances, resulting in new chemical compounds. Examples include combustion, rusting, and fermentation.
Radicals in Chemistry
- A radical is an atom or molecule that has unpaired electrons, making it highly reactive and unstable.
Role of Acids and Bases
- Acids donate protons (H⁺ ions) in chemical reactions, while bases accept protons. They play crucial roles in pH regulation, neutralization reactions, and various biochemical processes.
Atoms vs. Molecules
- The fundamental difference between an atom and a molecule is that an atom is the smallest unit of an element, while a molecule consists of two or more atoms bonded together, representing the smallest unit of a compound.
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Description
Test your knowledge of basic chemistry concepts with this Class 7 quiz. Answer questions about subatomic particles, density calculation, chemical symbols, and identifying chemical changes.
