Can someone help me with this please:(

c protons

Explanation:

I used go0glehope this helps

The nucleus is a collection of particles called protons, which are positively charged,

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.