Which of the following measurements is expressed to three significant figures?

A. 0.0006 m

B. 6066 mg

C. 6.40 * 10-7 km

D. 0.060 mm

If 89.6 joules of heat are needed to heat 20 g of iron from 30 c to 40 c, what is the specific heat of the iron in j/cg

Water can be formed according to the equation: 2h2 (g) + o2 (g) → 2h2o (g) if 8.0 l of hydrogen is reacted at stp, exactly how many liters of oxygen at stp would be needed to allow complete reaction?

What is electron affinity? A. the energy change that happens when a neutral atom gains an electron B. the energy change that happens when a neutral atom loses 2 electrons C.

If the ozone layer gets significantly thinner in your lifetime, what changes do you need to make in your lifestyle?

Which two parts of an atom determine the atom's mass?

Carbon-13 is an isotope of carbon. The atomic number of carbon is 6. How many neutrons does carbon-13 have?

What is the basic building block of matter to a chemist

Between magnesium and calcium, which has the highest ionization energy, and why?

approximately how many different cells can be found in a human cell? A. less than one hundred B. less than 10 C. more than a million D. more than one thousand

If I have a 200 L container filled with nitrogen at a pressure of 1.0 atm, how many moles of nitrogen are present at 25 degrees C?