Which of the following steps in a star's life cycle takes the longest?

A.

fusion of carbon atoms

B.

formation of a protostar

C.

fusion of hydrogen atoms

D.

fusion of helium atoms

Which statement best describes codominance and incomplete dominance? In codominance and incomplete dominance, both of the alleles are dominant. In codominance and incomplete dominance, neither of the alleles are dominant.

Given the bond energies below, calculate an estimate for ΔH (kJ) for the reaction: 2CO (g) + O2 (g) - > 2CO2 (g) Bond energy (kJ/mol) : C-O, 360; C=O, 799; CO (triple bond), 1071; O2, 498

John Dalton believed that: A. Atoms are made of mostly empty space. B. Chemical changes are the result of different atomic combinations. C. Violent chemical reactions can divide atoms into smaller particles. D. All of the above.

Which of the following could result from a substance that undergoes a physical change? A. It changes irreversibly. B. It undergoes phase change. C. It's elements composition is altered. D. its atoms rearrange to form a new molecule.

Consider the following compounds and suppose that 0.5 M solutions are prepared of each: NaI, KF, (NH4) Br, KF, KCN, KC2H3O2, CsNO3, and KBr. Which will have solutions that are (a) acidic, (b) basic, and (c) neutral

Which statement best describes the ideas of two scientists who studied properties of light? Newton and Maxwell had similar ideas about light being made of particles.

As transformações estão presente em nosso cotidiano, elas nunca param de acontecer, na sua maioria invisível a olho nu. Quais critérios é preciso observar para identificar se ocorreu transformação?

U human ear is measured in?

Is the earth older than any of the rock layers.

Problem page liquid hexane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water. what is the theoretical yield of water formed from the reaction of of hexane and of oxygen gas?