YO HELP PLS When the elements on the periodic table are arranged by increasing atomic numbers, the atomic mass generally increases as the atomic number increases. For some elements, however, the atomic mass of the element is lower than the atomic mass for the element that came before it. Explain how this could be possible.

Diego conducted an experiment to find out what kind of ball bounces the highest when dropped from a five-foot platform. he used a golf ball, a tennis ball, and a soccer ball. he dropped each ball from the balcony once. diego recorded his observations after each drop. what can diego do to best improve the reliability of his results? a) drop each ball from the platform three more times b) record his observations in more than one unit c) write at least two scientific questions after the experiment is complete d) share his results with other people who have done similar experiments you for the !

Which greenhouse gas is emitted when burn fossil fuels for energy? a.nitrogen b.oxygen c.carbon dioxide d.helium

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a.an ionic bond is formed between the oxygen and carbon atoms. b.four valence electrons are shared. c.two valence electrons are shared. d.valence electrons are shared between oxygen atoms.