Answer:
a. KCl, c. BaCl2 and e. LiF.
Explanation:
Hello,
In this case, we can identify the ionic compounds by verifying the difference in the electronegativity between the bonding compounds when it is 1.7 or more (otherwise it is covalent) as shown below:
a. KCl: 3.0-0.9=2.1 -> Ionic.
b. C2H4: 2.5-2.1=0.4 -> Covalent.
c. BaCl2: 3.0-0.8=2.2 -> Ionic.
d. SiCl4: 3.0-1.8=1.2 -> Covalent.
e. LiF: 4.0-1.0=3.0 -> Ionic.
Therefore, ionic compounds are a. KCl, c. BaCl2 and e. LiF.
Regards.
The mass is simply the product of volume and density. But
first, let us convert the volume into cm^3 (cm^3 = mL):
volume = 2.5 cups * (240 mL/cup)
volume = 600 mL = 600cm^3
So the mass is:
mass = 600 cm^3 * (1 g / cm^3)
<span>mass = 600g</span>
We know that
1) empirical formula of a compound is the representation of a molecules with the elements in simplest mole ratio.
2) the molar mass is the actual proportion of moles of elements present in a molecule
3) there is a simple ratio between the molar mass and empirical mass a molecule
Now let us solve each problem
1) empirical formula of
will be 
2) empirical formula of
will be 
3) empirical formula of
will be 
4) the molecular formula will be :

the molecular formula = 4 X empirical formula = 4 X CO = 
5) the mole ratio of Cl and Cr is 
empirical formula will be 
Different elements emit different spectra when their electrons get excited because each element has a different arrangement of electrons surrounding the nucleus. The energy levels in which the electrons can occupy are unique to a specific element. When an electron gets excited into a higher energy level, it will eventually relax back into its original state and emit light corresponding to that energy.