Which of the following is an endothermic reaction?

condensation of steam

combustion of methane

the reaction in a cold pack

an explosion

Imagine a balloon is made from a membrane that's permeable to water but not sucrose molecules. How would the concentration of sucrose inside the balloon be affected if the balloon is filled with a 50% sucrose solution and then placed in a beaker of

A go-cart has a mass of 90 kg. It moves at a rate of 3 m/s. What is its kinetic energy?

Butane C4 H10 (g), (Hf = - 125.7), combusts in the presence of oxygen to form CO2 (g) (Hf = - 393.5 kJ/mol), and H2O (g) (Hf = - 241.82) in the reaction: What is the enthalpy of combustion, per mole, of butane? Use

Describe how heat is transferred from one place to another by convection.

a certain quantity of argon gas is under 16 mmhg pressure at 16c in a 12 L vessal. How many moles of argon Are present?

The difference between isotopes for the same element will be found in the atoms' a. number of protons. b. number of electrons. c. number of neutrons. d. charges.

216 J of energy is required to raise the temperature of a piece of aluminum from 15.0º C to to 35º C. Calculate the mass of aluminum used. (Specific heat of aluminum = 0.90 J ∙ º C-1 ∙ g-1)

How much of the rock cycle can be observed directly? How much must be inferred? Think about both how long things take to happen in the cycle as well as where different parts of the cycle occur. Refer to specific parts of the cycle in your answer.

How are elements arranged in the Periodic Table? A. by their properties B. alphabetically C. by how much they are worth D. in the order they were discovered

If an iron nail is placed in a glass of water the nail will sink. Is the density of iron smaller than or larger than the density of water? explain