Which is true about the total mechanical energy of a pendulum in the absence of friction?

1. it exhibits constant velocity motion.

2. it exhibits simple harmonic motion.

3. it exhibits circular motion.

4. it exhibits only upward motion.

These models show the electron structures of two different nonmetal elements. which element is likely more reactive, and why? element 1 is more reactive because it has fewer electron shells and is toward the top of its group on the periodic table. element 1 is more reactive because it has more electrons in its valence shell and is farther to the right on the periodic table. element 2 is more reactive because it does not have a valence shell close to the nucleus, so it will attract electrons. element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.

How have the competing explanations' experiments on atoms affected the development of the atomic model?

Carbon-14 is a radioactive element that undergoes beta decay. which force is responsible for allowing carbon-14 to become stable? electromagnetic gravitational weak nuclear strong nuclear