From the early to middle neolithic (when copper tools were first made) to the present.
Not many people live long in the stone age. There were not doctors back in the stone age.
about 700 years
Begining of the metal age
The last ice age ended 100 000 years ago.
The Paleolithic age is generally assumed to have started 2.5 million years ago when early man first started to use stone tools, and to have lasted until about 10,000 years ago.
I think it is metal because it last long
Not many people live long in the stone age. There were not doctors back in the stone age.
about 300 years
How long germs can survive on metal can vary greatly. It would depend on the type of metal, the type of germ, and if the metal is wet or dry. On average, germs can last years in many cases.
Metal material is stronger than aluminum and it will last longer. It will also save you money in the long run.
about a 1 to 3 years
Ceramic knife sharpeners can last for several years if you use them weekly. Metal sharpeners last much longer.
Arcosteel last a very long time due to being metal.
the new stone age went for 4000 years 8000bc - 4000bc then the copper age began
309 years!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
about 700 years
12,000 years