A 92.7-g sample of a metal was heated to 99.7 °C and then plunged into 250.0 g of water at 23.0 °C. The resulting mixture obtained a temperature
of 30.0 °C. (The specific heat of water is 4.184 J/g.'C) How many joules of
heat did the water absorb?

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

All forces cause motion? true or false

Atoms contain subatomic particles called protons and neutrons. when these protons and neutrons spilt, a lot of energy is released