I think it could be C maybeee though
Answer:
???
Explanation:
i would help answer but your post has no diagrams or at least there not showing up
It is for safety if you come to a sudden stop like newtons law say if an object is in motion it stays in motion until a force stops it if the bike suddenly stopped then you would fly off because you wold still be going. and the gear helps protect you.
4. A
because PbCl2 is an ionic compound and it's solid, so it's a substance.
It cannot be mixture, because it's a pure molecule.
5. D
despite that both substances are gases, colorless they are different molecules, so they should have different either chemical and physical properties
6. C
this substance made from W atoms and others are made from molecules
