I recall learning about the bronze age in school. Why was bronze so important to the technological development of humans? Why not some other metal?
The first thing to remember is that the naming of eras such as the Stone Age or the Bronze Age is never done by those living during the period. It was always done by others much later.
To a certain degree, the reason why bronze was the first important alloy was luck. For whatever reason, design or mistake, someone at some stage during antiquity mixed copper and tin in a furnace and bronze was produced.
Prior to the use of bronze, copper was used. Copper being a soft metal became blunt very quick when used in tools and needed to be sharpened at frequent intervals. Additionally, copper corrodes easy compared to bronze. When bronze proved superior to copper, copper was abandoned as the metal of choice for tools. During the time of the Pharaohs in Egypt, copper was for tool making.
The Bronze Age was from about 3300 to about 800 BCE.
The first bronze made was arsenic bronze. When tin was discovered it replaced arsenic as the alloying metal. Tin bronze was better than arsenic bronze because the alloying process was more easily controlled and the resulting alloy was stronger and easier to cast.
Bronze became important because:
- It was a strong metal
- It was easy to cast
- It was easy to sharpen
- It maintained its sharp edge for a long time
- Weapons that maintained their sharp edges were very useful in battles. Likewise for non military uses such as knives and chisels
- It is resistant to salt water corrosion, making it useful for fittings in boats and ships
- It has a high resistant to corrosion and has fatigue endurance
- It does not oxidise beyond the surface
- It was useful as armour in ancient times
- It was fashioned into tiles for building construction
- It has a relatively low casting temperature
- When struck against a hard surface it does not generate sparks
It's heavy usage in ornamental work cannot be ignored. Statues and ornaments were important in ancient times and bronze was easy to produce and cast.
In short, there was a need for metals and bronze was available. Iron only started being used when the tin trade was disrupted. Steel wasn't invented until much later and until it was, iron was very soft, it corroded easily and it was not as useful as bronze.
I'd like to add to what @Fred said.
Bronze wasn't the first. Before the Bronze Age, there was a comparatively brief Copper Age [also this]. Copper is comparatively abundant, and it sometimes naturally occurs in pure state (nuggets), as well as ores.
In some places, polymetallic ores were used for producing copper. Early metalworkers noticed that the resulting "copper" had different properties. I've used quotes, because it wasn't copper anymore: accidentally, it was bronze. Subsequently, alloying materials were added on purpose.