Which change occurs when an atom in an excited

state returns to the ground state?

(1) Energy is emitted.

(2) Energy is absorbed.

(3) The number of electrons decreases.

(4) The number of electrons increases.

A carbon forms one bond to an X atom plus three more bonds to three hydrogen atoms. If the hybridization to X has 81% p-character, what is the H-C-X bond angle in degrees to the nearest tenth of a degree?

A serious risk factor associated with the operation of a nuclear power plant is the production of (1) acid rain (2) helium gas (3) greenhouse gases, such as CO2 (4) radioisotopes with long half-lives

Whats 2 + 2? correct answers only

A student is running an experiment in which 74.8 grams of bai2 is needed, but the only jar of reagent in the lab is labelled barium iodide dihydrate.

How many moles of na + are present in 343 ml of a 1.27 m solution of na2so4?

Pf3cl2 is a nonpolar molecule. based on this information, determine the f-p-f bond angle, the cl-p-cl bond angle, and the f-p-cl bond angle. enter the number of degrees of the f-p-f, cl-p-cl, and f-p-cl bond angles, separated by commas (e. g.

What is the empirical formula of a substance that contains 2.64g of C, 0.444g H and 3.52g of O

How many liters of space will 7.80 moles of methane gas (CH4) occupy at STP

Which is an example of the flow of heat through conduction? Hot air rises to the top of the room A hot-air balloon rises into the sky Heat flows from a hot liquid to a pot handle Heat causes winds to blow from the water to the land

Jin listed some common thermal insulators and conductors in a chart. A 2-column table with 2 rows. The first column labeled Insulators has entries rubber, air. The second column labeled Conductors has entries copper, X.