Atoms and atomic theory
When orbitals of identical energy (degenerate orbitals) are available, electrons
tải về 0.52 Mb. Chế độ xem pdf
|
English-for-Chemistry-1-After-lesson-1
- Điều hướng trang này:
- Lesson 4. CHEMICAL BONDING 4.1 Listening: Covalent bonds Complete the paragraph by filling the blanks
| 3. When orbitals of identical energy (degenerate orbitals) are available, electrons
initially occupy these orbitals singly. In line with this rule, known as Hund's rule, an atom tends to have as many unpaired electrons as possible. This behaviour can be rationalised by saying that electrons, because they all carry the same electric charge, …(5)…. They do this by seeking out empty orbitals of similar energy in preference to pairing up with an electron in a half-filled orbital. Q1. Complete the reading text above by writing one of these sentences or phrases in each blank (two of them do not belong to the text) 1. they must have different values of m s 2. try to get as far apart as possible 3. filling of orbitals is based on the periodic table 4. maximizes the energy of the atom 5. minimizes the energy of the atom 6. electrons in orbitals are shown as arrows 7. the s subshell consists of one orbital with a capacity of two electrons Q2. - Find prepositions in the text. Q3. - Make groups of students. - Each group prepares 5 questions. - Each group takes turn to ask and answer questions from the other group. Grammar note: Preposition + Noun V-ing English in chemistry 1 – 2017 TS. Nguyễn Tuyết Phương – TS. Trần Thu Phương 10 Lesson 4. CHEMICAL BONDING 4.1 Listening: Covalent bonds Complete the paragraph by filling the blanks In this video you are going to learn about covalent bonds, how they are made and how they are …(1)…. If you haven’t seen it already, first have a look at our video “Structure and bonding”. Only the noble gases …(2)… naturally as single atoms. All the other elements of the periodic table have partially filled valence shells or outer electron shells. Atoms bond by swapping or sharing electrons in their outer shells. When very different atoms …(3)… like metals and nonmetals, they normally swap electrons. This is ionic bonding. When similar atoms react like nonmetals combining with other nonmetals, they …(4)… electrons. This is covalent bonding. Nonmetals are found on the right hand side and upper part of the …(5)… table. Some common nonmetals are carbon, nitrogen, oxygen, and the halides. They have shells of electrons that are normally half or more than half full of electrons. Since they have a strong …(6)… for few additional electrons, it is energetically unfavorable for them to lose electrons. So they share electrons by overlapping orbitals. This makes a bonding orbital or tải về 0.52 Mb. Chia sẻ với bạn bè của bạn:
|