Argon-39 has a half-life of 269 years. How long will it take for 52.5 g of a 60.0 g sample to decay to its daughter isotope?

How many molecules (not moles) of nh3 are produced from 8.95*10-4 g of h2?

What reaction occurs when two amino acids are put together?

Which best explains why openness is important

Which pair of atoms has the highest electronegativity difference? A. H - S B. H - Cl C. N - H D. O - H E. C - H

6.0 g of copper was heated from 20 degree c to 90 degree c. How much energy was used to heat cu?

Identify the element that chlorine forms a covalent bond with

A child pulls a sled up a snow-covered hill. The child does 405 J of work on the sled. If the child walks 15 m up the hill, how large of a force must the child exert?

A piece of glass with a mass of 32.50 g specific heat of 0.840 J/g*°C and an initial temperature of 115 °C was dropped into a calorimeter containing 57 g of water (specific heat 4.184 J/g*°C).

Which of the following is the most likely description of the product or products of a double-displacement reaction? A) one new compound B) two new compounds C) oxygen and energy D) one new compound and an element

A balloon is filled with 12L of air at a pressure of 2 atm. What is the volume of ballon if the pressure is changed to 3 atm?