Which of the following are correct? electrons generally occupy the lowest energy orbital first. the c atom has two unpaired electrons. the he atom has two electrons that have parallel spin in its 1s orbital. the arrangement of the orbitals is the same in a multielectron atom and a single-electron atom. in the li atom, the 3s, 3p, and 3d orbitals have different energies. the he atom has one electron each in 1s and 2s orbitals.

Electrons generally occupy the lowest energy orbital first. The C atom has two unpaired electrons. In the Li atom, the 3s, 3p, and 3d orbitals have different energies.

Explanation:

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance