A fictitious element X is composed of 10.0 percent of the isotope 55 X, 20.0 percent of the isotope 56 X, and 70.0 percent of the isotope 57 X. Estimate the atomic mass of element X.

Asample contains 16.75 g of the radioisotope u-236 and 50.25 g of its daughter isotope, th-232. how long did it take for decay to take place if one half-life of u-236 is 23 million years? 46 million years 69 million years 92 million years 115 million years

Which is a characteristic of mixtures?

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.