1s22s22p 3s23p64823d3
How many valence electrons does this atom have?
A.2
B.3
C.5
C.11

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)

Use the de broglie's wave equation to find the wavelength of an electron moving at 4.5 × 106 m/s. show your work. note: h= plank's constant (6.62607 x 10-34 j s)

How many joules of heat are required to raise thetemperature of 750 g of water from 11.0 °c to 19.0 °c?