Compare and contrast experiments and observations

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

An earthquake’s epicenter can be determined from arrival time data recorded on a(

Select the correct answer.look at this nineteenth-century illustration of london. which explanation best relates this illustration to changes in britain in the 1800s? a.factory workers in cities lost their livelihood because of the lack of housingb.industrialization narrowed the inccome gap between landowners and workers.c.the migration of workers from rural to urban areas resulted in overcrowded citiesd.the spread of railways allowed farmers to sell produce far from where it was grown.