What is the meaning of a value of - 400 kJ in a reaction? The reaction requires 400 kJ of heat. The reaction releases 400 kJ of heat. The products have 400 kJ of heat energy more than the reactants. The reaction will not occur.

What happens to molecules in gas when energy is added?

De que está echo nuestro sol

A 2.25 g sample of an unknown gas at 63 ∘ C and 1.10 atm is stored in a 1.15 L flask. What is the density of the gas? density: g / L What is the molar mass of the gas? molar mass:

12. The number of protons and neutrons tells us: | a. The principle quantum number b. The reactivity of the element e C. The atomic mass d. The atomic number . Both a and c

What is the number of electrons that can be held in the first orbit closest to the nucleus

In solid KCl, which has the same solid state structure as NaCl (simple cubic unit cell), the distance between the ions is 314 pm. Calculate the length of the edge of the unit cell.

Planck's constant is approximately equal to which of the following? The product of the uncertainties in electron position and electron momentum. The sum of the uncertainties in electron position and electron momentum.

Which is the MOST accurate description about how the different types of feedback mechanisms work

Which of the following equations violates the law of conservation of mass? A) 2Al + 6HCl yields 2AlCl3 + 3H2 B) Na2C2O4 + Pb (NO3) 2 yields PbC2O4 + 2NaNO3 C) AgNO3 + LiCl yields AgCl + LiNO3 D) 3Ca + 2Cr (NO3) 3 yields 3Ca (NO3) 3 + 2Cr

Which of the following is a true statement about energy? a. energy can be created and destroyed. b. energy is never created nor destroyed. c. energy is easily created, but cannot be destroyed. d. energy cannot be converted from one form to another.