Tools and equipment regularly to identify defective ones?

What type of interaction occurs between the r groups of valine and isoleucine in a tertiary structure? view available hint(s) what type of interaction occurs between the r groups of valine and isoleucine in a tertiary structure? salt bridge disulfide bridge hydrogen bond hydrophobic interaction

The rate constant for the reaction below is 6.2 x 10−5 mol l−1 s −1. if the initial concentration of a is 0.0500 m, what is its concentration after 115 s?

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 300j of energy to the room?unit: