What pressing problem did the invention of the cotton gin solve?

A. removing seeds from cotton fiber

B. efficiently harvesting raw cotton

C. quickly plowing the cotton fields

D. irrigating the fields of cotton plants

the answer is A.

Lithium is a metal with an oxidation number of 1 + and oxygen is a nonmetal with an oxidation number of 2-. Which chemical formula represents the compound formed by these two elements?

Niels Bohr had a theory about the structure of an atom. Which part of his theory has been proven wrong? A. An atom is mostly empty space. B. Atoms are rearranged in chemical reactions. C. The nucleus is made up of protons and neutrons. D.

You are asked to give a presentation on why it is important to protect the ozone layer. What is one thing you could say?

What factor affects sensation A. emotions B. motives C. experiences D. physiological conditions

A boat crosses a 200m wide river at 3m/s, north relative to water. The river flows at 1m/s as shown. What is the velocity of the boat as observed by a stationary observer on the river back from the boat departed?

Which of these is a property of most nonmetals? Question 3 options: poor conductors of both heat and electricity reactive lustrous appearance good conductor of heat, but not electricity malleable when a solid

Not all energy sources derive their energy from the sun. Choose the three from the list below that derive their energy from sources other than the sun. chemical heat light geothermal nuclear tidal

Suppose your car is equipped with tire pressure monitoring system (TPMS) and the tire pressure is 34.0 psi on a 98F day in california. You decided to take a road trp to Alaska where the temperature drops to 20 F.

Which sound would be loudest? O A. a wave with an amplitude of 1.0 OB. a wave with an amplitude of 0.1 OC. a wave with an amplitude of 0.5 OD. a wave with an amplitude of O

How much work is done when a 4.0-newton box is carried horizontally a distance of 2.0 meters at a constant velocity?