When someone refers to the “periods” of the periodic table, what are they referring to? a. the metalloids b. the rows of the table c. the different historical models of the table d. the groups of elements with similar properties

When someone refers to the “periods” of the periodic table, what are they referring to?

A period in the periodic table is a horizontal row. ... Each next element in a period has one more proton and is less metallic than its predecessor. Arranged this way, groups of elements in the same column have similar chemical and physical properties, reflecting the periodic law.

So the closest answer would be B

4 meters

Given in the question,

mass of dog = 40kg

potential energy posses by dog = 1568 J

Formula to use

where m - mass of object

           g - acceleration due to gravity = 9.8 m/s²

           h - height

Plug values in the formula

1568 = 40(9.8)(h)

h = 1568/392

h = 4 m