Need brainliest***a substance has a half-life of 60,000 years and an initial mass of 1,000 grams. how many years will pass before only 250 grams of the substance's parent material is left?

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called

just finished the test, the answer is d, greg is the least cost-effective because he charges the most for the project