Choose one contact and one non contact force from the following list, then in your own words explain why you believe they are a contact or non-contact force. Feel free to utilize other resturces to support your claims. Answers should be at least 3-4 sentences each. Types of Forces Contact: Friction, Tension, Elastic, Reaction, Air Resistance Non-Contact: Gravity, Nuclear, Electrostatic, Magnetic

This is the substance(s) formed in a chemical reaction.

Directions: count the number of atoms. ar co2 na3po4 so3 nac2h3o2

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.