Which of the following refers to the horizontal rows of the periodic table

Find the momentum for a 2.6-kg brick parachuting straight downward at a constant speed of 8.4 m/s .

What do elements in a family tend to share. a.) similar periods b.) similar groups c.) similar atomic symbols d.) similar chemical properties and characteristics

The charge on an electron is 1.60218 × 10−19 c and its mass is 9.10939 × 10−31 kg. how strong a magnetic field must be experienced by the electron if its path is a circle of radius 5.5 cm? answer in units of t.