How many lenses does a compound microscope have

Define valence electrons and identify the number of valence electrons in an element using periodic table.

In Florida the constellation Orion is seen in the night sky during the winter months. during the summer Orion can't be seen why is Orion only visible during part of the year.

An arrow is fired directly horizontal off a cliff that is 10.0 meters tall with a velocity of 65.5m/s how long is the arrow in the air?

A hot-air balloon of diameter 12 m rises vertically at a constant speed of 11 m/s. A passenger accidentally drops his camera from the railing of the basket when it is 19 m above the ground.

Multiple lunar eclipses occur each year. How is it possible that each one can look different than the others? Explain.

Explain how Copernicus concluded that stars were farther away than planets. Draw a diagram showing how this principle applies to another example.

Some car manufacturers claim that their vehicles could climb a slope of 42 ∘. For this to be possible, what must be the minimum coefficient of static friction between the vehicle's tires and the road?

Which of the following has the least impact on the environment? A. solar power B. nuclear power C. fossil fuels D. hydroelectric power

Why is steel better to conduct sound than air? use the words density and compression in your answer

4. How does density affect refraction of a lightwave?