Question

9.what are some properties/characteristics of copper?

1. a)what is the first man - made metal alloy? what metals does it consist of?

b)what was its contribution to humanity in ancient times?

1. what makes metals conductive?
2. how does mixing tin with copper atoms make the resulting alloy( bronze ) harder?
3. what did chemical analysis of the liberty bell reveal about the crack?
4. what is an instrument used to see actual atoms in bronze?
5. what is the orderly arrangement of atoms in metals called?

16.what is the technique to visualize atoms of metals?

Explanation:

1. Copper is a good conductor of heat and electricity, has high ductility and malleability, and a characteristic reddish - brown color.
2. a) The first man - made metal alloy is bronze, which consists of copper and tin. b) In ancient times, bronze was used to make tools, weapons, and artworks, which improved productivity and had cultural significance.
3. Metals are conductive due to the presence of free - moving electrons in their atomic structure.
4. When tin is mixed with copper atoms to form bronze, the different - sized atoms disrupt the regular lattice of copper, making it harder for the layers to slide over each other, thus hardening the alloy.
5. Chemical analysis of the Liberty Bell may have revealed information about its composition and how impurities or uneven composition could have contributed to the crack.
6. A transmission electron microscope (TEM) can be used to see actual atoms in bronze.
7. The orderly arrangement of atoms in metals is called a crystal lattice.
8. Techniques such as transmission electron microscopy (TEM) and scanning tunneling microscopy (STM) can be used to visualize atoms of metals.

Answer:

1. Good conductor of heat and electricity, high ductility and malleability, reddish - brown color.
2. a) Bronze, copper and tin. b) Used for tools, weapons, artworks, improved productivity, cultural significance.
3. Presence of free - moving electrons.
4. Different - sized atoms disrupt copper lattice, prevent layer sliding.
5. Information about composition and contribution to crack.
6. Transmission electron microscope (TEM).
7. Crystal lattice.
8. Transmission electron microscopy (TEM), scanning tunneling microscopy (STM).