Which is most likely the ionic compound?
David observed properties of four different compounds,
only one of which is an ionic compound His observations
are shown in the chart
Compound
w
Observations
Is a hard solid, melts
at 44° C, has a
molecular structure
Is a brittle solid, does
not conduct
electricity in water,
has a crystal
structure
Is a hard solid,
conducts electricity,
has a molecular
structure
Is a brittle solid,
melts at 801° C

State one advantage and one disadvantage of using a plane mirrior as a driving mirrior

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 790 n/m. it is initially at rest on an inclined plane that is at an angle of 28 degrees with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is k = 0.14. in the initial position, where the spring is compressed by a distance of a = 0.18 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. 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.

He latent heat of vaporization for ethyl alcohol is 854 j/g. the amount of energy, rounded to the nearest whole number, needed to change 5.20 grams of ethyl alcohol from a liquid to a gas is