Answer the following question given this paragraph: There are other forms of radioactive dating. Rocks, for example, can sometimes be dated based on the decay of 238 U . The decay series for 238 U ends with 206 Pb , so that the ratio of these nuclides in a rock is an indication of how long it has been since the rock solidified. The original composition of the rock, such as the absence of lead, must be known with some confidence. However, as with carbon-14 dating, the technique can be verified by a consistent body of knowledge. Since 238 U has a half-life of solidified about. Q: What is the term for dating a rock based on composition decay? Choices: - carbon dating - fuel dating - safe dating - radioactive dating A:
radioactive dating

Answer the following question given this paragraph: Eris is the largest known dwarf planet in the solar system. It is 27 percent larger than Pluto ( Figure above ). Like Pluto and Makemake, Eris is in the Kuiper belt. But Eris is about 3 times farther from the Sun than Pluto. Because of its distance, Eris was not discovered until 2005. Early on, it was thought that Eris might be the tenth planet. Its discovery helped astronomers realize that they needed a new definition of "planet. " Eris has a small moon, Dysnomia. Its moon orbits Eris once about every 16 days. Q: What are small planets in our solar system called? Choices: - scrub planets - Tiny planets - light planets - dwarf planets A:
dwarf planets

Answer the following question given this paragraph: In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it won't harm delicate tissues of the lungs. Q: Which part of the body has mucus and hair to trap dust and also warms and moistens air so to not harm lung tissue? Choices: - the tongue - the throat - the ear - the nose A:
the nose

Answer the following question given this paragraph: The atomic number of an element is the number of protons in the nucleus of each atom of that element. An atom can be classified as a particular element based solely on its atomic number. For example, any atom with an atomic number of 8 (its nucleus contains 8 protons) is an oxygen atom, and any atom with a different number of protons would be a different element. The periodic table ( Figure below ) displays all of the known elements and is arranged in order of increasing atomic number. In this table, an element's atomic number is indicated above the elemental symbol. Hydrogen, at the upper left of the table, has an atomic number of 1. Every hydrogen atom has one proton in its nucleus. Next on the table is helium, whose atoms have two protons in the nucleus. Lithium atoms have three protons, beryllium atoms have four, and so on. Since atoms are neutral, the number of electrons in an atom is equal to the number of protons. Therefore, hydrogen atoms all have one electron occupying the space outside of the nucleus. Q: An atom can be classified as a particular element based solely on its what? Choices: - light number - spectrum - ability - atomic number A:
atomic number