Answer:
You can measure mineral hardness with The Mohs' Scale.
Hope this helped :)
A. It has mass.
Air is matter, and can't be seen thus not all matter can be seen.
Any liquid or gaseous is matter (water, air, etc.)
Since it can be liquid or gaseous it doesn't have to maintain it's shape and size to be matter.
These are called igneous rocks due to them being made from lava from an volcanoe eruption,
I'm assuming this is the same image that was posted before, therefore the answer is "gene flow" which occurs through population groups by natural selection and other factors.
Microscope allowed us to find known parasites, micro living things.
Technology allowed us to inherit knowledge on different plants and animals
