Which are the simplest pure substances that cannot be broken down into any other substances

True or false? a well oiled machine has no friction

Which is a biological sign of aging?

A girl pushes a 60-kilogram box for a distance of 3 meters with a force of 4 Newtons into seconds. What is the power of the girl

A 4-m * 5-m * 6-m room is to be heated by a base-board resistance heater. It is desired that the resistance heater be able to raise the air temperature in the room from 5 to 25°C within 17 min.

Which statement would best explain a property of all elements? A. All elements exist in the solid phase B. All elements are purr substances. C. All elements have six electrons. D. All elements are metal.

Which of the outer planets are most like Earth? How?

The pressure inside a champagne bottle can be quite high and can launch a cork explosively. Suppose you open a bottle at sea level. The absolute pressure inside a champagne bottle is 6 times atmospheric pressure; the cork has a mass of 7.

Using a cathode ray tube, Thomson confirmed that atoms must have an overall positive charge. atoms are made of particles that have a negative charge. electrons in atoms must have varying amounts of energy. electrons are only found in the nucleus.

A ball is rolled along the inside of a partial hoop lying flat on a table. which path will the ball follow when it gets to the end of the hoop?

What pattern of material movement found in the Earth system tracks how an element moves from living to nonliving parts? a. rock cycle b. calcium cycle c. carbon cycle d. none of the above