What is Zeff for a 4d electron in a Zr atom? The atomic number of Zr is 40.

What type of reaction is represented by the following example? 2co2 (g) + 4h2o (l) + 1452 kj 2ch3oh (l) (g) + 3o2 (g) exothermic endothermic

Asmall amount of a solid is added to water. the observation made after fifteen minutes is shown in the figure. which of these solids has been probably added to water? a) oil b) sand c) sugar d) wood chips

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line