A compound differs from a mixture in that a compound always has a?

1. homogeneous composition

2. maximum of two components

3. minimum of three components

4. heterogeneous composition

Very important! How do enzymes catalyze chemical reactions? By giving up electrons By positioning substrates and destabilizing bonds By acting as substrates and forming new products By being used up in the reaction

Which of the following has the shortest wavelength? A) green light B) radio waves C) infared radiation D) X rays86 Which of the following enables your body to make vitamin D? A) ultraviolet radiation B) infared waves C) gamma rays D) visible light

What is the most common way to increase retenation of anlyates in gas choromatography analysis

If you have 120. mL of a 0.100 M TES buffer at pH 7.55 and you add 3.00 mL of 1.00 M HCl, what will be the new pH? (The pKa of TES is 7.55.)

Which compound reacts with an acid to form a salt and water?

Energy leaves the sun as light from a region called the?

How many moles of co2 are produced when 10 mol of propane (c3h8) is burned in excess oxygen?

Why are the spheres representing nitrogen and oxygen different colors

How many moles are in 16.94g of water?

Two compound samples are found to have the same mass percentages of the same elements. what can you conclude about the two samples