to answer the following questions 1. How many tons of coal, oil, and gas are estimated to exist in the earth? a. 2200 b. 4 million c. 3300 billion d. 270 million ​

Elements and compounds are pure substances that cannot be broken down physically into a simpler substance. a physical change doesn’t break the bonds between atoms of a substance or form new ones. compounds can be broken down by a chemical change. a chemical change breaks chemical bonds and/or forms new ones between atoms of a substance. what simple substance would a compound break into? the basic elements that make it up! for example, if you passed a very strong electric current through water you’d break the chemical bonds in water and be left with oxygen and hydrogen. which of the following is an example of a chemical change? a separating water into different glasses b breaking frozen ice cubes with a hammer c running an electric current through water d boiling water to evaporate it on a stove

Which of these is a major trend in land plant evolution? a) the trend toward smaller size b) the trend toward a gametophyte-dominated life cycle c) the trend toward a sporophyte-dominated life cycle d) the trend toward larger gametophytes

What occupation did muhammad have before the first revelation