Radioisotopes tell scientists that earth is how old?
a. 65 million years
b. 500 million years
c. 4.5 billion years
d. 13.4 billion years

State the formula for density in words and mathematical symbols

If the element whose electric configuration ends in the d sublevel, the element is calssified as? a.inner transition b.noble gases c.representative d. transition

Which statement correctly identifies the scientific question and describes why the question is scientific? question 1 refers to the supernatural.question 2 reflects a moral or social value.question 3 refers to something that can be measured.question 4 reflects a question that can’t be observed.