1. How many moles are contained in 103.4g of sulfuric acid? a) 2.9 * 10^22 molecules of sulfuric acid
b) 5.18 * 10^24 molecules of sulfuric acid
c)12.1 * 10^23 molecules of sulfuric acid
d) 6.35 * 10^23 molecules of sulfuric acid

2. Which of the following statements is true?
a) 1 mole H atoms = 6.02 * 10^23 H atoms
b) 1 mole pennies = 6.02 * 10^23 pennies
c) 6.02 * 10^23 H atoms have a mass of 1.0g
d) The formula mass of O= 32.00 amu

One mole of NH3 contains:
a) 1.806 * 10^24 atoms of hydrogen
b) 1.4g of nitrogen atoms
c) 6.02 * 10^23 molecules of ammonia
d) 7.0g of ammonia

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.