To what element does Thorium-230 (atomic number-90) decay when it emits an alpha particle (42He) ?

a. 22688Ra

c. 22886Rn

b. 23090Ra

d. 22286Rn

According to periodic trend, which of the following most likely has the highest ionization energy? Na Al Si Ar

The rusting of iron is due to its reaction with oxygen. An iron nail weighing 8.531 g was left outdoors for a period of one year. After the one year it was found to have a mass of 12.197 g. How many grams of oxygen did the nail react with

To which class of elements does copper (cu) belong: metal, metalloid, or nonmetal? identify three other elements in this class.

Pentaborane b5h9 (s) burns vigorously in o2 to give b2o3 (s) and h2o (l). what is δh° for the combustion of 1 mol of b5h9 (s) ? substance δh°f (kj/mol) b2o3 (s) - 1273.5 b5h9 (s) + 73.2 h2o (l) - 285.8

The molecular mass of the compound is 137.32 g/mol. what is the molecular formula of the compound? pcl2 pcl3

Formula for hydroselenic acid

The branch of chemistry that is the study of the composition, properties, and reactions of matter is called

According to the article, HOW has the discovery of the Mimivirus influenced scientists' ideas about viruses? А Since it acts differently than other viruses, scientists think it could lead to a vaccine for cancer B.

Consider the two electron arrangements for neutral atoms A and B. Are atoms A and B the same element? A - 1s2, 2s2, 2p6, 3s1 B - 1s2, 2s2, 2p6, 5s1 yes or no

Match the following terms to their correct examples Conduction Convection Radiation Water warming on a stove The sun warming the earth A spoon resting in a cup of tea gets hot