An unknown element is a mixture of isotopes ¹⁵¹X (atomic mass = 150.99 amu) and ¹⁵³X (atomic mass = 153.03 amu). The average atomic mass of X is 151.36 amu. What is the percent abundance of ¹⁵³X?

What are the primary responsibilities of a chemical engineer involved in "r& d"? develop large scale manufacturing operations discover new products and processes training of new chemists determine products needed by consumers

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.

Analyze the reaction to determine whether the reaction is exothermic or endothermic. explain your reasoning.