For the element Praseodymium, which has 59 electrons, what is the electron configuration? 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f3

1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 3

1s4 2s4 2p6 3s4 3p6 3d10 4s4 4p6 4d10 4f6

1s 4 2s 4 2p 6 3s 4 3p 6 3d 10 4s 4 4p 6 4d 10 4f 6

1s1 2s1 2p3 3s1 3p3 4s1 3d5 4p3 5s1 4d5 5p3 6s1 4f7 5d5 6p3 5f7 7s1 5f7 6d3

1s 1 2s 1 2p 3 3s 1 3p 3 4s 1 3d 5 4p 3 5s 1 4d 5 5p 3 6s 1 4f 7 5d 5 6p 3 5f 7 7s 1 5f 7 6d 3

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f3 5s2 5p6

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

Consider the following reaction at equilibrium. 2co2 (g) 2co (g) + o2 (g) h° = -514 kj le châtelier's principle predicts that the equilibrium partial pressure of co (g) can be maximized by carrying out the reaction a. at high temperature and high pressure b. at high temperature and low pressure c. at low temperature and low pressure d. at low temperature and high pressure e. in the presence of solid carbon

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?