Answer:
SiH4 is nonpolar and BBr3 is nonpolar and SiF4 is nonpolar.
Explanation:
SiH4 is a non-polar compound. Though the Si–H bonds are polar, as a result of different electronegativities of Si and H. However, as there are 4 electron repulsions around the central Si atom, the polar bonds are arranged symmetrically around the central atom having a tetrahedral shape hence they cancel out making the compound nonpolar.
SiF4 is a nonpolar molecule because the fluorine atoms are arranged symetrically around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out just like in SiH4.
The 3 bromine atoms all lie in the same plane thus the geometry of the compound will be trigonal planar. The BBr3 will be non polar because the three B-Br bonds will cancel out each others' dipole moment given that they are in the same plane.
Answer:
<h2>500 J</h2>
Explanation:
The kinetic energy of an object can be found by using the formula

where
m is the mass
v is the velocity
From the question
m = 1.6 kg
v = 25 m/s
We have

We have the final answer as
<h3>500 J </h3>
Hope this helps you
Answer:
Its molecules are made up of 60 carbon atoms joined together by strong covalent bonds. Molecules of C 60 are spherical. There are weak intermolecular forces between molecules of buckminsterfullerene. These need little energy to overcome, so buckminsterfullerene is slippery and has a low melting point.
Explanation:
Answer:
I would write "terrestrial/lives on land during all life stages" between the frog and pigeon branches
Explanation:
Jaw evolution has started with fish, so i'd place that before the perch, evolution of four limbs is next and I would plate it between the perch and the frog. Evolution of an egg has ensured that organisms remain terrestrial during all stages of life and don't need to rely on water to lay their eggs. So I would place that between the frog and the pigeon. True mammary glands and true hair, as we know it formed on mammals so i'd place that between the pigeon and the rats (although synapsids evolved similar structures long before birds even existed). And lastly, I would place "walking on two legs" between rats and human branches. Because our ancestors evolved bipedalism relatively late.