Do boys lose the ability to scream after puberty ? not shout scream​

Which of the following is a question of morality? a.) delierately reporting false data b.) accidentally reporting false data c.) kepping a sloppy record of experimental observation d.) condition a drug experiment which will harm a lab rats

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

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?