Answer: 8, which is basic
Explanation: The hydrogen ion concentration is 1.0 x 10^-8 mole per liter. Using [H+] = 1.0 x 10 -(pH) the pH is 8. A pH above 7 is basic.
Answer:
A = 0.75 ×10² KJ.
B = 3.9 ×10³ dg
C = 0.22 × 10² μl.
Explanation:
A = 7.5 ×10⁴ j to kilo joules
7.5 ×10⁴ / 1000 = 0.75 ×10² KJ.
Joule is the smaller unit while kilo joule is the larger unit. One kilo joule equals to the thousand joule that's why we will divide the given value by 1000 in order to convert into KJ.
B = 3.9 ×10⁵ mg to decigrams.
3.9 ×10⁵ / 100 = 3.9 ×10³ dg
Decigram is larger unit while milligram is smaller unit. One decigram is equal to the 100 milligram. In order to convert the given value into decigram we have to divide the value by 100.
C = 2.21 ×10⁻⁴ dL to micorliters
2.21 ×10⁻⁴ ×10⁵ = 0.22 × 10² μl.
Deciliter is bigger unit then micro liter . One deciliter equals to the 100000 micro liters. In order to convert the dL into micro liter we have to multiply the given value with 100000.
The atomic number (Z) of the 3 elements F, Ne, and Na, are 9, 10, and 11.
Explanation:
Now Z refers to the number of protons in the element's nucleus, and protons are POSITIVELY charged particles. So a fluoride ion, F−, has 10 electrons rather than 9 (why?), a neutral neon atom has 10 electrons, and a sodium ion, Na+, also has 10 electrons (why?).
So the 3 species are ISOELECTRONIC; they possess the same number of electrons.
You should look at the Periodic Table to confirm the electron number. Elements are (usually) electrically neutral (sometimes they can be ionic if they have lost or gained electrons). If there are 10 positively charged protons in the nucleus, there are NECESSARILY 10 electrons associated with the NEUTRAL atom. I don't know WHY I am capitalizing certain WORDS.
You might ask why sodium will form a positive ion, Na+, whereas F forms a negative ion, F−. This again is a Periodic phenomenon, and explicable on the basis of the electronic structure that the Table formalizes.
Neutral metals tend to be electron-rich species, which have 1 or more electrons in a valence shell remote from the nuclear charge. On the other hand, neutral non-metals have valence electrons in incomplete shells, that do not effectively shield the nuclear charge. The demonstrable consequence is that metals lose electrons to form positive ions, whereas non-metals gain electrons to form negative ions.
Answer:
The soup that is not too hot to eat would be better
Explanation:
because the flavours would be fresher than if it is leftover
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
