Arrange the following substances in order of decreasing magnitude of lattice energy.

cao, naf, sro, kcl

CaO > SrO > NaF > KCl  

Explanation:

The lattice dissociation energy (LE) is the energy needed to convert 1 mol of the solid crystal into gaseous ions.

A simplified formula for lattice energy is

where q₁ and q₂ are the ionic charges, r is the interionic distance, and κ is a constant.

Thus, lattice energies increase as the

The compounds written in their ionic forms are

Ca²⁺O²⁻, Na⁺F⁻, Sr²⁺O²⁻, and K⁺Cl⁻

We can separate them into two groups:

 (1,1) = NaF and KCl

(2,2) = CaO and SrO

The (1,1) compounds have smaller lattice energies than their (2,2) counterparts.

K⁺ and Cl⁻ are larger ions than Na⁺ and F⁻, so the lattice energy of KCl is less than that of NaF.

Sr²⁺ is a larger cation than Ca²⁺, so the lattice energy of SrO is less than that of CaO.

The order of lattice energies is

CaO > SrO > NaF > KCl

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.