Is it correct to say that only one observable change accompanies a chemical change?

Silicon has three naturally occurring isotopes. Silicon-28 has a mass of 27.98 and a relative abundance of 92.23%. Silicon-29 has a mass of 28.98 and a relative abundance of 4.68%. Silicon-30 has a mass of 29.97 and a relative abundance of 3.09%.

H2 (g) + I2 (g) ⇌2HI (g) Initially, only H2 and I2 were present at concentrations of [H2]=3.65M and [I2]=2.70M. The equilibrium concentration of I2 is 0.0100 M. What is the equilibrium constant, Kc, for the reaction at this temperature?

Where is the only place the weak necular force can be seen

A 1.0 g sample of hydrogen reacts completely with 19.0 g of fluorine to form a compound of hydrogen and fluorine. What is the percent composition by mass of hydrogen in this compound?

What volume of nitrogen is needed to produce 250.0 L of ammonia gas at STP?

The standard enthalpies of formation of ions in aqueous solutions are obtained by arbitrarily assigning a value of zero to H + ions; that is, ΔH° [H f ⁺ (aq) ] = 0. (a) For the following reaction HCl (g) ⟶H₂O H⁺ (aq) + Cl⁻ (aq) ΔH° = - 74.

Heat is the total potential energy of a substance that can be transferred. TRUE FALSE

How does Earth's rotation axis cause seasons to change?

Which of the following can be considered evidence of a chemical change? (Click the 4 that apply) A. Evaportation B. Production of a new substance C. Production of Bubbles D. Melting E. Color change F. Dissolving G. Freezing H. Heat is released

The decomposition of hi has a rate constant of 1.80 * 10-3 m-1s-1. how much hi remains after 8.50 min if the initial concentration of hi is 4.78 m?