Why is it necessary to use models to study sub micro scope objects such as atoms and molecules?
a) these objects do not exist in the real world
b)these objects are too far away to see
c)these objects are too small to see
d)objects can only be described mathematically

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true

The density of the solid phase of a substance is 0.90 g/cm3 and the density of the liquid phase is 1.0 g/cm3. a large increase in pressure will a. lower the freezing point b. raise the freezing point c. lower the boiling point d. raise the triple point e. lower the triple point

Which of the following is an example of how telecommunication devices people do their jobs? a.) a security guard checks the time using a digital watch. b.) a banker does some quick math using a solar calculator. c.) a nurse uses a digital thermometer to take a patient’s temperature. d.) a construction worker reports in to his office using a cell phone.