Calculate the weighted average atomic mass for this unknown element with three isotopes: X-44 with a mass of 43.955 amu and a relative abundance of 2.1%, X-
40 with a mass of 39.963 amu and a relative abundance of 96.9%, X-42 with a
mass of 41.959 amu and a relative abundance of 0.7%. Identify the unknown
element based upon the weighted average atomic mass.

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

Which substance is a steroid? cholesterol fatty acid monosaccharide trans fat

Which statement describes the phase change that occurs when dry ice is placed in an open container at room temperature?