44. (a) N2O3 (b) SF4 (c) AlCl3 (d) Li2CO3
46. H Br
δ+ δ−
48. The metallic potassium atoms lose one electron and form +1 cations,
and the nonmetallic fluorine atoms gain one electron and form –1 anions.
K → K+
+ e–
19p/19e–
19p/18e–
F + e–
→ F–
9p/9e–
9p/10e–
The ionic bonds are the attractions between K+
cations and F–
anions.
50. See Figure 3.6.
52. (a) covalent…nonmetal-nonmetal (b) ionic…metal-nonmetal
54. (a) all nonmetallic atoms - molecular (b) metal-nonmetal - ionic
56. (a) 7 (b) 4
58. Each of the following answers is based on the assumption that nonmetallic
atoms tend to form covalent bonds in order to get an octet (8) of
electrons around each atom, like the very stable noble gases (other than
helium). Covalent bonds (represented by lines in Lewis structures) and lone
pairs each contribute two electrons to the octet.
(a) oxygen, O
If oxygen atoms form two covalent bonds, they will have an octet of electrons
around them. Water is an example:
H O H
(b) fluorine, F
If fluorine atoms form one covalent bond, they will have an octet of electrons
around them. Hydrogen fluoride, HF, is an example:
H F
(c) carbon, C
If carbon atoms form four covalent bonds, they will have an octet of electrons
around them. Methane, CH4, is an example:
H H
H
H
C
(d) phosphorus, P
If phosphorus atoms form three covalent bonds, they will have an octet
Answer: 3.06m/s
Explanation:
Distance covered by swimmer = 220 m
Time taken by swimmer = 72 s.
Velocity = ?
Recall that velocity is the rate of change of distance per unit time. it is measured in metres per second.
Velocity = Distance / time taken
Velocity = 220m / 72seconds
Velocity = 3.055 m/s (approximate to 3.06m/s)
Answer:
Explanation:
Porcelain. Porcelain is perhaps one of the most popular materials used to make bathroom basins. Porcelain itself is a ceramic material, and comes in two common forms: vitreous china and fine fire clay.
homogeneous mixture not pure, but is spread out the same throughout
concentration, a measure of the amount of solute dissolved in a solvent
mixture,two or more substances that do not chemically combine, salt and pepper
solute,substance that is dissolved in the solution
