Select all the correct answers. Which two generallzations can be made based on what you know about cycles of matter in a closed systern?
ONew matter Is added, and old matter is destroyed.
O Matter changes Its physical form, allowing it to return to lts original state.
O The amount of matter within the systern rermains the sarne.
O Matter and energy can cross the boundaries of the systern.
O The cycle has a well-defined starting and stopping point.

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

C=59(f−32)the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true? a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of 59 degree celsius. a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit. a temperature increase of 59 degree fahrenheit is equivalent to a temperature increase of 1 degree celsius. a) i onlyb) ii onlyc) iii onlyd) i and ii only