The ground state of carbon is (   )

Why does the existence of intermediate state in the 4-level laser can promote the production of laser beam? A: reach population inversion between ground state and metastable state B: reach population inversion between ground state and intermediate state C: reach population inversion between ground state and pumped state D: reach population inversion between intermediate state and metastable state

Which of the following statements about density functional theory is not correct? A: B3LYP is a hybrid functional. B: TD-DFT can be used to calculate the properties of excited states. C: One can get a DFT molecular wavefunction from DFT calculation. D: For nondegenerate ground state, the wavefunction and all other molecular properties are uniquely determined by the ground-state electron probability density.

When there are two electrons in the N-layer of a ground state atom, The M-layer must have A: 8 electrons B: 10 electrons C: 18 electrons D: 8-18 electrons

He was severely criticized ________that he didn’t work hard. A: for the ground B: on the ground C: in the ground D: under the ground

Which of the following statements is true: ( ) A: RO• is not a very reactive species B: RO• is not thought to be an intermediate in the smog-forming process. C: RO• is a free radical D: RO• is readily formed by the action of stable hydrocarbons and ground state NO2

Which types of discrimination are illegal in the UK? A: Discrimination on ground of sex B: Discrimination on ground of race C: Discrimination on ground of age D: Discrimination on ground of religious beliefs E: Discrimination on ground of sexual orientation

When the tornado touches the ground, it does ___________________. It usually touches the ground for only about _______________, and it usually travels along the ground for only about ________________, but during that one minute, buildings are __________, trees are ____________ out of the ground, small objects are ________________, and sometimes people are ___________or _________.

1) Have you ever heard ground collision?2) what are the possible reasons for ground collision?3) What can be done to avoid ground collision?

When the normative method determines the formula for calculating bearing capacity of ground, fa is（ ） A: characteristic value of bearing capacity of ground B: modified characteristic value of bearing capacity of ground C: correction coefficient of bearing capacity of ground D: uncertain