For states with larger values of n that admit a d subshell, the d subshell is at even higher energy than the p subshell. In fact, its energy is higher than that of the s subshell for the n 1 state. With this in mind, 1. Which of the following are valid ground-state electron structures?
1. 1s2 2s2 2p63 s2 3p6 3d2
2. 1s2 2s2 2p6 3s2 3p6 3d11
3. 1s2 2s2 2p6 3s2 3p6 4s2 3d5
A. 1
B. 2
C. 3
D. 1 and 2
E. 1 and 3
F. 2 and 3
2. Which of the following is not a valid electron structure for an atom in its ground state? Use the fact that electrons fill the lowest energy states first and keep in mind the number of allowed states for each subshell.
A. 1s2 2s2 2p6 3s3
B. 1s2 2s2 2p6 3s2 3p4
C. 1s2 2s2 2p6 3s2
D. 1s2 2s2 2p6 3s2 3p5
E. 1s2 2s2 2p5

Automobile fuel efficiency is often measured in miles that the car can be driven per gallon of fuel (mpg). heavier cars tend to have lower fuel efficiencies (lower mpg ratings). which variable (weight or fuel efficiency) is most naturally considered the explanatory (predictor) variable in this context?

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. the block's initial mechanical energy is 9.472 j.b. if the spring pushes the block up the incline, what distance l in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.