Which of the following questions would be answered using concepts from chemistry? a. how do atoms combine to form new substances? b. how much energy was transferred when two cars hit each other? c. how fast will a sled be moving when it reaches the bottom of a hill? d. how much force is required to move a chair?

Look at the reaction below: ca(hco3)2 --> caco3 + co2 + h2o first, balance the reaction. once balanced, use dimensional analysis or another method to find out how many moles of carbon dioxide will be produced if we start with 16.5 moles of calcium bicarbonate (calcium hydrogen carbonate). = mol of co2 number needs to be reported to three significant figures.

Un cierto gas tiene un volumen de 800ml a 80°c y 600ml a 80°c y 600mmhg de presión. ¿cual será el volumen del gas a condiciones normales? sí el gas es oxígeno, ¿cuál será su peso? y ¿cuántas moléculas están presentes en el sistema?

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?