A pure substance that cannot be separated into simpler substances by physical or chemical means. A pure substance composed of two or more elements that are chemically combined.
1 calorie is equal to 4.184 Joules.
Answer:
A trigonal pyramid is a tetrahedron with one vacant vertex.
Explanation:
<em>How does a trigonal pyramid differ from a tetrahedron so far as molecular geometry is concerned? </em>
<em>Bond angles in the tetrahedral molecule are 120°, while those for trigonal pyramid are 109.5°.</em> FALSE. Bond angles in the tetrahedral are 109.5°, while those for the trigonal pyramid are slightly lower than 109.5° due to the repulsion of the unshared pair of electrons on the central atom.
<em>A trigonal pyramid is a tetrahedron with two vacant vertex.</em> FALSE.
<em>A trigonal pyramid is a tetrahedron with one vacant vertex.</em> TRUE. This is the geometry of NH₃, in which the central atom is bonded to 3 atoms and has 1 unshared pair of electrons.
<em>Bond angles in the tetrahedral molecule are 109.5°, while those for trigonal pyramid are 120°.</em> FALSE.
<em>A tetrahedron has a square base, while the base of a trigonal pyramid is a triangle.</em> FALSE. Both have a triangular base.
Answer:
the rate of reaction would decrease
Explanation: