A certain radioactive element has a half-life of one hour. if you start with 1.0 gram of the element at noon, how much of the radioactive element will be left at 2 p. m.? 0.50 grams 0.25 grams 0.125 grams 0.0 grams

Elemental magnesium consists of three isotopes: 24mg with an accurate mass of 23.99 amu, 25mg with an accurate mass of 24.99 amu, and 26mg with an accurate mass of 25.99 amu.

Why do gases diffuse faster than liquids? Gas particles have more kinetic energy a liquid does not have as many particles liquids have less volume to diffuse through liquids have more pressure to overcome when diffusing

Describe your understanding of atoms and their subtomic particles

How many moles of carbon atoms are there in 0.500 mol of C2H6?

Which of the following is a region that produces cells in a plant? a. Cork cambium c. Vascular cambium b. Apical meristem d. All of the above

The density of an aqueous solution of nitric acid is 1.36 g/ml and the concentration is 2.48 m. what is the concentration of this solution in percent by mass?

In a crystal lattice of an ionic compound, A. Kind of a given charge are clustered together B. Ions are surrounded by ions of the opposite charge C. A sea of electrons surrounds the ions D. Neutral molecules are present

Discuss why two objects of made of the same type of matter at the same starting temperature with different masses increase in temperature at different rates when the same amount of thermal energy is transferred to each object.

An isotope contains 56 protons, 54 electrons, and 74 neutrons. What is the identity of the isotope?

How many ozone particles are needed to form 24 particles of oxygen gas?