A teacher wants to perform a classroom demonstration that illustrates both chemical and physical changes. Which would be the best demonstration that she could use?

The unit "troy ounce" is often used for precious metals such as gold (Au) and platinum (Pt) (1 troy ounce = 31.103 g). (a) A gold coin weighs 2.41 troy ounces. Calculate its mass in grams.

What is the whole mass of air surrounding earth?

Individuals who share a common cultural background and a common sense of identity are known as an ethnic group. 1) True 2) False

Carbon is transferred from seawater to atmosphere through the process of A. diffusion B. excretion C. photosynthesis D. respiration

How much heat does your body lose when 3.45 g of sweat evaporates from your skin at 25 âc? (assume that the sweat is only water.) the heat of vaporization of water at 25 âc is 44.0 kj/mole?

How does heat transfer takes place between any two systems?

Hydrate name of CaCl2 * 8 H2O

Calculate the heat evolved from a mixture of 14.1 l of sulfure dioxide

Which stament best describes a solution

Which answer accurately describes the difference between speed and velocity? Read each answer choice carefully. Question 4 options: A. If speed is constant, then velocity is also constant. B. Speed requires direction.