Please help : A gas absorbs 6.9 kJ of heat and does 1.7 kJ of work. Calculate AE.

If e is the symbol for an element, which two of the following symbols represent isotopes of the same element? 1. e2. e3. ea.1 and 2c.1 and 4b.3 and 4d.2 and 3

Which of the following is the molecular formula for a simple sugar? a. cooh b. h2o c. oh d. c6h12o6

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost