Below is a data table on properties of different substances. Iron Oxidizes Solid at room temperature Melting point 2800 degrees F Attracted to a magnet
Mercury Oxidizes Liquid at room temperature Melting point -37 degrees F Weakly attracted to a magnet
Which statement best describes a chemical property of iron?

oxidizes
solid at room temperature
attracted to a magnet
melting point 2800 degrees F

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

the objects have the same charge.

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.