A mystery element "A" has two stable isotopes X-100 which occurs 20% of the time and X-120 which occurs 80% of the time. What is the average mass of element "A"?

A-100 amu

B-104 amu

C-116 amu

D-120 amu

21. consider the following chemical reaction: n2+ o2 2 no if 10.0 g of n2 reacts with excess oxygen then how many grams of no can be formed? a) 10.7 g b) 21.4 g c) 32.9 g d) 42.8 g page 4 of 8

Which of these is an example of pseudoscience? a) predicting the time of sunrise based on data on position of earth b) predicting the date of the moon phases based on data on position of earth c) predicting eclipses based on the position of the sun and the moon d) predicting future events in a person's life based on the position of the moon

What is the chemical name of the compound ti2o3? use the list of polyatomic ions and the periodic table to you answer.