The atomic number is

A. use the atomic number

B. mass number - atomic number

C. number of protons and neutrons in an atom

D. number of proton in an atom

A change in heat whether endothermic or exothermic is always a clear indication of a chemical change true or false?

How many kilojoules are required to heat 0.500 g of water from 20.3 degrees Celcius to 29.7 degrees Celcius? How many Calories? Show your work and watch sig figs.

What is a scientist?

Poly (lactic acid) (pla) has received much recent attention because the lactic acid monomer [ch3ch (oh) cooh] from which it is made can be obtained from carbohydrates rather than petroleum. this makes pla a more "environmentally friendly" polyester.

Choose all the answers that apply. Which of the following are general characteristics of animals? they are mobile they have nervous systems they are heterotrophs they have specialized tissue they have spinal cords

What kind of chemical bond does salt have?

How does phosphorus enter the human body?

When a reaction occurs between atoms with ground state electron configuration 1s2 2s1 and 1s2 2s2 2p5 the predominant type of bond formed is

How does heat transfer takes place between any two systems?

Hydrate name of CaCl2 * 8 H2O