What is true of a covalent bond?
a. it is the electrostatic attraction between oppositely charged particles..
b. it is the sharing of electrons by overlapping orbitals.
c. it involves the exchange of electrons from one atom to another.
d. it involves the sharing of neutrons between two nuclei.

The covalent bond is the sharing of electrons by overlapping orbitals.

B

Explanation

Covalent bond is defined as the bonding formed by mutual sharing of two or more valence electrons between the elements.

It obeys valence bond theory. The mutual sharing of valence electrons occurs by overlapping of the valence orbitals as stated by valence bond theory.

The mutual sharing of valence electrons lead of stabilize both the elements.

The electrons are not transferred completely to another element for stabilizing purpose.

The valence electrons will remain in their parent element shell only, but they will be shared with another element valence shell electrons by overlapping.

So the option (b) is true for covalent bond, the remaining options (A) and (C) are true for ionic bond.

away from the curb

explanation:

the wheels would then hit the curb if it started to rolling, decreasing the chance of an accident.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"