Which Of These Is An Indication that a chemical reaction occurred

A. formation of gas

B. boiling of a substance

c. melting of a substance

d. freezing of a substance

He orbital period of an object is 2 * 107 s and its total radius is 4 * 1010 m

What is the number of neutrons in an atom with atomic mass of 35, three energy levels, and 7 valence electrons?

You notice that two brothers have the same eye color. You are describing their genotype phenotype genetic makeup

In a constant‑pressure calorimeter, 60.0 mL of 0.300 M Ba (OH) 2 was added to 60.0 mL of 0.600 M HCl. The reaction caused the temperature of the solution to rise from 22.74 ∘ C to 26.83 ∘ C.

Classify each of the following as an observation, a law, or a theory. (a) All matter is made of tiny, indestructible particles called atoms. (b) When iron rusts in a closed container, the mass of the container and its contents does not change.

Rank the temperatures from the highest to the lowest. 133F 351K 25C 273K 146C 58F 95F

Calculate the density of sulfuric acid if 35.4 mL of the acid weighs 65.14 g.

Where the single machos?

A reaction will be spontaneous only at low temperatures if both ΔH and ΔS are negative. For a reaction in which ΔH = - 320.1 kJ/mol and ΔS = - 86.00 J/K · mol. Determine the temperature (in °C) below which the reaction is spontaneous.

Is it possible for a balloon with an initial internal pressure equal to 250.0 kPa to naturally expand to four times its initial volume when the temperature remains constant and the atmospheric pressure is 101.3 kPa?