Which of the following describes an exothermic reaction?

O

A. AHI, reactants = 0

O

B. AHf, reactants = AHf, products

O

C. A He, reactants > AHf, products

O

D. A He, reactants < AH, products

A certain rifle bullet has a mass of 9.81 g. Calculate the de Broglie wavelength of the bullet traveling at 1097 miles per hour.

Which statement describes the electron sea model for metallic bonding? -This model involves electrons held tightly between atoms. -This model explains all properties of metals. -This model involves electrons moving among bands of orbitals.

What mass of calcium metal contains the same number of atoms as 24.3 g of magnesium?

What is happening to the electrons if an ionic compound is formed when magnesium reacts with oxygen

Solve this problem using the appropriate law. (Remember that) What is the pressure of 1.9 mols of nitrogen gas in a 9.45 L tank and at a temperature of 228 K?

Where did the earth hold most of its original water

Giovanni created this chart to study for an exam. A 2-column table titled common ionic compounds. The first column labeled compound has entries sodium hydroxide (N a O H), iron oxide (F e O), calcium chloride (C a C l subscript 2), calcium carbonate

Consider the two electron arrangements for neutral atoms A and B. What is the difference between atom A and atom B? A - 1s22s22p63s1 B - 1s22s22p65s1 Atom B has lost some inner electrons.

Choose all the answers that apply. Which of the following has kinetic energy? rolling ball, moving car, book on a table, spinning top, or a falling tree.

Which of the following statements about the suns feature is true?