7. The model of the universe that suggests that the sun is the center of the universe was first brought by

A. Brahe.

B. Ptolemy.

C. Copernicus.

D. Kepler.

Identify the true statements about surface tension. Molecules along the surface of a liquid behave differently than those in the bulk liquid. Mercury has a lower surface tension than water.

What is the PH of a solution whose [H+] is 0.0007

What type of energy does a stone have when it hits the ground? Electrical energy Kinetic energy Potential energy Radiant energy

298.34 K = °C 28.42°C = k

Ammonia reacts with oxygen to produce nitrogen and water according to the equation below. What is the enthalpy of the reaction?

This decomposition is first order with respect to phosphine, and has a half‑life of 35.0 s at 953 K. Calculate the partial pressure of hydrogen gas that is present after 70.5 s if a 2.20 L vessel containing 2.

A new element has two isotopes, one with a mass of 40.0 amu and the other with a mass of 42.0 amu. the atomic weight is 40.50 g/mol. pick the true statement a. the isotope at 42.0 amu is less abundant b. the element has 19 protons and 21 neutrons c.

Which of the following wave is most like visible light? a sound wave moving through the air a radio wave moving through space a water wave moving through a lake a sound wave moving through wood

What holds the atoms together in a covalent bond? the attraction between the shared electrons and protons in each nucleus a weak electron cloud the attraction of the opposing ions the crystal lattice structure

A container with the ability to expand and contract has its pressure changed from 5.0 atm to 7.5 atm at constant temperature. It the original volume was 4.0 L, what is the new volume?