A scientist is studying a radioactive element that has a half-life of 63 years. Choose the correct answers from the drop-down menus to complete each statement about the element. It will take
years for half of the sample to decay.

In 189 years,
of the sample will be left.

Scientists can figure out how old a sample is by multiplying the
by the length of the half-life.

How did the northern u.s. change during the 19th century? select the best choice from the answers provided. a. it became more industrial. b. it became more agrarian. c. it became less populated. d. it became less diverse

Plz which of the following statements about the fugitive slave act of 1850 is not accurate? a. marshals you refuse to arrest a suspected fugitive could be find $1000. b. slave owners had to present evidence an african-american in the north was a fugitive slave. c. any person who provided food or shelter to a fugitive slave could be find $1000 and placed in jail for six months. d. it required of federal marshals to arrest any african-american suspected of being a runaway slave.

During the 1980s, profit from the sale of weapons to iran was used to stop the communists in costa rica. start a proxy war in el salvador. support the contras in nicaragua. stage a coup d’état in guatemala.