1-What is the modern periodic table? 2-Compare and contrast the periods and groups of the modern periodic table.

3-In the modern periodic table shown in Figure 1 above, find the element named lead (Pb). How many protons do atoms of lead have? To which class of elements does lead belong?

4-Which groups of the modern periodic table contain elements that are classified as metalloids?

Liquid water turns into water vapor at which step in the water cycle? a. precipitation o b. water run off c. evaporation d. condensation

How do tides affect the organisms living in intertidal zones? a. no organisms live in intertidal zones due to the tumultuous environment. b. the mechanical forces of the waves keeps the organisms clean. c. only plants live in intertidal zones because the animals float away with the waves and never return. d. the mechanical forces of the waves can dislodge the organisms from their habitat.

Which equation is used to calculate the magnetic force on a charge moving in a magnetic field