Building blocks of matter Flashcards
1
Q
What is meant by the term Element
A
A pure substance that cannot be broken down further by chemical means.
2
Q
Mixture
A
Two or more elements that are bonded physically.
3
Q
Compound
A
Two or more elements that are bonded chemically.
4
Q
Distinguish between an atom and a molecule
A
An atom is defined as the smallest building block of matter while a molecule is an electrically neutral group of two or more atoms held together by chemical bonds
5
Q
State the difference between mixtures and compounds
A
Mixtures
- Components separated by physical means
- Composition may vary
- No chemical change takes place
- Properties of mixtures come from the element that makes up the mixture
Compounds
- Components are separated by chemical means
- Composition is always the same
- Chemical change takes place
- Properties of components are different from the properties of elements
6
Q
What is meant by the term Alloys
A
A mixture of a metal with one or more other elements
7
Q
What are the properties of Alloys
A
- Harder
- Stronger
- More resistant to corrosion
8
Q
State a few examples of alloys and their uses
A
- Brass, which is made of copper and zinc and used to make musical instruments and ornaments.
- Bronze, which is made of copper and tin and used to make medals.
- Stainless steel, which is made of Iron, Nickel, and Chromium and used to make cutlery and kitchen sinks.
