What is the half-life of an isotope if 125 g of a 500 g sample of the isotope remains after 3.0 years?

a.) 3.5 years

b.) 4.5 years

c.) 1.5 years

d.) 2.5 years

What is an alloy of copper and zinc?

Convert 0.600 atm of pressure to its equivalent in millimeters of mercury. Express the pressure numerically in millimeters of mercury.

Which planet has the highest surface temperature in the solar system

In order to do work on an object how do force and direction relate

Water is called the "universal solvent." Which statement best explains this description with respect to ionic compounds?

It requires 0.0780L of a 0.12 M HCl solution to completely neutralize 0.0280L of an unknown LiOH solution. What is the concentration of the unknown LiOH solution?

Which best describes the two ways that energy is measured A. In convection and in temperature B. In temperature and in radiation C. In radiation and in convection D. In wavelength and in temperature

What usually happens to the outer electrons of metallic atoms when they combine chemically with nonmetallic atoms?

How many moles of ca atoms are in 534.0 g ca?

Select all that apply. reactions between atoms occur when: an atom seeks to fill its outer shell of electrons an atom seeks to balance its positive and negative charges the reaction will result in paired electrons