Oxygen in the air combines with the copper statue to form copper oxide, which is green. which of these is the correct chemical reaction for this? a) cu + o → cuo eliminate b) cu + o2 → cuo c) cuo → cu + o2 d) 2 cu + o2 → 2cuo

Match each object to its description: a. coma of a comet b. comet tail c. oort cloud haze surrounding a nucleus created by solar wind. hypothetical sphere around the solar system

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size

Areaction in which products can react to re-form reactants is