an unknown element x has the following isotopes: ²⁵x (80.50% abundant, mass = 25.03 amu) and ²⁷x (19.50% abundant, mass = 26.98 amu). what is the average atomic mass of x in amu?

Which two statements are true about a system? 1. a system is a group of objects analyzed as one unit. 2. energy that moves across system boundaries is conserved. 3. there’s only one way to define the boundaries of a system. 4. all systems are made by humans.

How was the sat? what type of questions for math, writing and reading. did anyone get a near perfect score and if so how long did it take to study. i am very stressed and want to get at least a 1450.

Ricks boss often appriciates him for his work.how is rocks boss affecting his proformence