A compound differs from a mixture because it

a. always remains frozen even at high temperatures.

b. is formed from two cations.

c. always contains the same elements in the same proportion.

d. can form only in the presence of heat energy.

Rank these elements according to highest ionization energy. Be, C, O, Ne, B, Li, F, N

Which sae standard (s) must be referred to on the label of approved hfc-134a refrigerant recycling machines?

Which of the following surrounds a cell, keeping the organelles inside and allowing some things to move into and out of the cell? * A. Cell Membrane B. Cytoplasm C. Nucleus

1. Put the layers of Earth in order from densest to least dense. A. Crust, Mantle, Inner core, Outer Core B. The inner core, Mantle, Outer core, Crust C. Crust, Mantle, Outer core, Inner Core D. The inner core, Outer core, Mantle, Crust 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

Which type of soil holds the least water

Eq-43 which type of fire extinguisher should be onboard a vessel with a permanently installed fuel tank

5. Identify a suitable method that would be used to separate mixture of the follow [b]Water and ethanol c]Table salt dissolved in water d] iodine and potassium Pul the table below

How much energy is needed to convert 57.3 grams of ice at 0.00°c to water at 75.0°c? specific heat (ice) = 2.10 j/g°c specific heat (water) = 4.18 j/g°c heat of fusion = 333 j/g heat of vaporization = 2258 j/g?

A certain first-order reaction (A→productsA→products) has a rate constant of 9.90*10-3 s-1s-1 at 45 ∘C∘C. How many minutes does it take for the concentration of the reactant, [A][A], to drop to 6.