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Large populations of the southern bark beetle have recently moved into the forests of the Appalachian Mountains. These insects have killed large numbers of pines and severely impacting their ecosystems. This infestation is an example of

Kudzu is a type of invasive:

Give an example of each of the following:  Natural active immunity –  Natural passive immunity –  Artificial active immunity –  Artificial passive immunity –   

Which white blood cells comprise 20% to 30% of the circulating WBCs and are the cells that function in the body’s third line of defense against mainly viral infections?

Which isopropyl alcohol is most effective at killing microbes? 

Combustion analysis of 25.0 g of cumene (C9H12) determined that the sample contained 2.52 g of hydrogen. What is the percent by mass of carbon present in cumene?

Combustion analysis of 25.0 g of octane (C8H18) determined that the sample contained 3.97 g of hydrogen. What is the percent by mass of carbon present in octane?

How much energy is required to raise the temperature of 40.9 g of copper by 38.1oC? The specific heat capacity of copper is 0.385 J/g°C.

An unknown compound has the following mass percent composition: 63.15% carbon, 5.30% hydrogen and 31.55% oxygen. What is the empirical formula of the compound.

Consider the reaction: 2Al(s)  +  6HCl(aq) → 2AlCl3(aq) + 3H2(g) If a sample of 4.0 moles of Al is added to a solution containing 2.0 moles of HCl, how many moles of H2 are formed?