20 A student draws the model shown below. Sun

Earth

Which of these best compares the conditions at Location X and Location Y?

F It is day at Location X and night at Location Y.

GIt is winter at Location X and summer at Location Y.

H There are more hours of daylight at Location X than at Location Y.

1 The moon is brighter when viewed from Location X than when viewed from Location Y.

Read the given expression. x = number of protons − number of core electrons which of the following explains the identity of x and its trends across a period? x is the effective nuclear charge, and it remains constant across a period. x is the screening constant, and it remains constant across a period. x is the effective nuclear charge, and it increases across a period. x is the screening constant, and it increases across a period.

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?

Which fact represents evidence for the big bang theory?