Which of the following is an example of conservation of mass?

a. mass before = 3g mass after = 3g
b. mass before = 4g mass after = 3g
c. mass before = 6g mass after = 12g

What neutral atom is isoelectronic to mn+4

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

Two metal blocks that have slightly different temperatures are placed next to one another. after five minutes, they both have lower but equal temperatures. according to the law of conservation of energy, what  most likelyhappened? energy was created inside the blocks.energy was destroyed inside the blocks.energy was absorbed into the blocks from outside the system.energy was transferred from the warmer block to the cooler block.