A tree was chopped down and cut up in a local forest. The tree changed in shape.

Which kind of change took place?

A. change in reaction

B. phase change

C. physical change

D. chemical change

How many valence electrons configuration of oxygen?

Fluoride ion is poisonous in relatively low amounts: 0.2 g of F - per 70 kg body weight can cause death. Nevertheless, in order to prevent tooth decay, F - ions are added to drinking water at a concentration of 1 mg of F - ion per L of water.

For a solution containing 6.38% para-diclorobenzene by mass in benzene, the density of the solution as a function of temperature (t) in the temperature range 15 to 65°C is given by the equation, rho (g/ml) = 1.5794 - 1.836x10-3 (t-15).

How many moles of Sodium Hydroxide - NaOH are in a 35.65g sample of NaOH?

Select the four TRUE statements below describing the standard free energy change (ΔG) and the equilibrium constant (Keq). Options: 1. The standard free energy change is a function of enzyme concentration in the reaction. 2.

Which reaction is endothermic? H2 (g) + ½ O2 (g) → H2O (g), ΔH = - 57.82 kcal ½N2 (g) + O2 (g) + 8.1 kcal → NO2 (g) ½N2 (g) + 3/2H2 (g) → NH3 (g) + 11.0 kcal C (diamond) + O2 (g) → CO2, ΔH = - 94.50 kcal

If a temperature increase from 10.0 ∘C to 21.0 ∘C doubles the rate constant for a reaction, what is the value of the activation barrier for the reaction

Chlorine released from chlorofluorocarbons (cfcs) reacts with ozone in the atmosphere to form oxygen. the proposed reactions are cl (g) + o3 (g) →clo (g) + o2 (g) clo (g) + o (g) →cl (g) + o2 (g) identify the species that acts as a catalyst and the

What does one of the elements in the periodic table have?

Children's reactions to divorce often include which of the following groups of behaviors?