Elements want to have how many electrons in their outer shell?

2 or 8

only 8

only 2

What is a relatively soft layer of upper mantle called?

You are given two carts A and B. They look identical and you are told they are made of the same material. You place A at rest at an air track and give B a constant velocity directed to the right so that it collides elastically with A.

Two crates, a and b, sit at rest side by side on a frictionless horizontal surface. the crates have masses ma and mb. a horizontal force f⃗ is applied to crate a and the two crates move off to the right.

A liquid of density 1370 kg/m 3 flows steadily through a pipe of varying diameter and height. At Location 1 along the pipe, the flow speed is 9.67 m/s and the pipe diameter d 1 is 12.9 cm. At Location 2, the pipe diameter d 2 is 16.7 cm.

Mirage is due to ... A. unequal heating of different parts of the atmosphere B. magnetic disturbances in the atmosphere C. depletion of ozone layer in the atmosphere D. equal heating of different parts of the atmosphere

How do whales bats and dolphins use echolocation? A To scare away predators B To attract mates C To orient them selves and find food D To tell animals of there species where they are

How much force would be needed to move a car with the mass of 100kg to an acceleration of 5m/s/s?

A pendulum bob is made from a sphere filled with water. What would happen to the frequency of vibration of this pendulum if the sphere had a hole in it that allowed the water to leak out slowly?

Elias serves a volleyball at a velocity of 16 m/s. The mass of the volleyball is 0.27 kg. What is the height of the volleyball above the gym floor when its total mechanical energy is 41.70 J? Round to the nearest number.

Which of the following is the best description of a graph? A. Equations that can be plotted B. A representation of an equation C. Independent and dependent variables D. x and y lines