The rock record indicates that photosynthesis began on earth about 3.5 million years ago.
a. true
b. false

Write the complete balanced equation for the reaction between lead (iv) oxide (pbo2) and water (h2o).

Which statement accurately describes the relationship between air pressure, air density, or altitude? as altitude increases, pressure increases.as altitude increases, air density increases.air pressure and density are lowest at sea level.denser air exerts more pressure than less dense air.

Which of these best describes an ionic bond?