Everything on Earth is made up of matter, that is, of elements and of the compounds they form. Matter is everything that you can touch/see/feel or smell. Chemistry is the study of matter and the changes that take place within that matter. There are three main states of matter: solids, liquids and gases. Each of these states is also known as a phase. A solid is matter with a rigid shape and a fixed volume that does not change much with temperature. A liquid has a fixed volume but not a fixed shape and it takes the shape of its container. Its volume may alter with changes in temperature and pressure. A gas has neither fixed volume nor shape, as it expands to fill its container completely. Its volume is very sensitive to temperature and pressure. Matter is composed of different kinds of atoms. An atom is made up of electrons, protons and neutrons. Protons and neutrons are in the nucleus, the centre of the atom. Electrons spin very quickly around the nucleus. Electrons have a negative charge, protons have a positive charge and neutrons have no charge. The number of protons always equals the number of electrons in an atom, so the atom is neutral. If some electrons are added or removed, the atom becomes charged and is then an ion. A molecule is a particle containing two or more atoms chemically bonded together. Matter has physical and chemical properties. Physical properties include density, melting point, boiling point, freezing point, colour or smell. An example of chemical properties is the way elements combine with each other in reactions. An element is matter that consists of only one kind of atom. A compound is a substance consisting of two or more chemically bonded elements, with a fixed ratio determining the composition. Elements and compounds can move from one phase to another when special physical forces are present. One example of those forces is temperature. When temperature changes, the phase can change. You can see water vapour over a boiling pot of water. That vapour (or gas) can condense and become a drop of water. If you put that drop in the freezer, it becomes a solid. No matter what phase it is in, it is still water. It still has the same chemical properties QUESTIONS: 1. Why do you think it is important to study chemistry? 2. What is METTER? 3. What is electrons? 4. What is protons? EXERCISES: 1. What am I? Choose from: electron, ion, neutron, nucleus, proton. a. I’m the centre of the atom, I contain protons and neutrons. I’m the ... b. I move around the nucleus. I’m an ... c. I’m positively charged. I’m a ... d. I’ve no charge. I’m a ... e. I’m an electrically charged atom. I’m an ... 2. Use how, how many, what, which to complete the questions. a. ... is matter? b. ... can matter exist? c. ... of the three states of matter have a fixed shape? d. ... of them have no fixed volume? e. ... are atoms made up of? f. ... of the constituents of an atom are outside the nucleus? g. ... are the properties of matter classified? h. ... kinds of atoms are there in an element? ACTIVE VOCABULARY: English Uzbek Russian Earth Yer Земля Atom Atom Атом Temperature Harorat Температура Chemical Kimyoviy Химический Electron Elektron Электрон Neutron Neytron Нейтрон Proton Proton Протон Matter Modda Материя Molecule Molekula Ion Ион Ion Молекула Erdagi hamma narsa materiyadan, ya'ni elementlardan va ular hosil qilgan birikmalardan iborat. Materiya - bu teginish / ko'rish / his qilish yoki hidlash mumkin bo'lgan hamma narsa. Kimyo - materiya va uning ichida sodir bo'ladigan o'zgarishlarni o'rganadigan fan. Moddaning uchta asosiy holati mavjud: qattiq, suyuqlik va gazlar. Bu holatlarning har biri faza sifatida ham tanilgan. Qattiq jism - qattiq shaklga ega va qattiq hajmga ega bo'lgan, harorat bilan deyarli o'zgarmaydigan modda. Suyuqlik o'zgarmas hajmga ega, lekin o'zgarmas shaklga ega va u o'z idishining shaklini oladi. Uning hajmi harorat va bosimning o'zgarishi bilan o'zgarishi mumkin. Gazning o'zgarmas hajmi ham, shakli ham yo'q, chunki u idishni to'liq to'ldirish uchun kengayadi. Uning hajmi harorat va bosimga juda sezgir. Materiya har xil turdagi atomlardan tashkil topgan. Atom elektronlar, protonlar va neytronlardan tashkil topgan. Proton va neytronlar yadroda, atom markazida joylashgan. Elektronlar yadro atrofida juda tez aylanadi. Elektronlar manfiy zaryadga ega, protonlar musbat zaryadga ega va neytronlar zaryadsizdir. Protonlar soni har doim atomdagi elektronlar soniga teng, shuning uchun atom neytraldir. Agar ba'zi elektronlar qo'shilsa yoki olib tashlansa, atom zaryadlanadi va keyin ion bo'ladi. Molekula - bu bir-biriga kimyoviy bog'langan ikki yoki undan ortiq atomlarni o'z ichiga olgan zarracha. Modda fizik va kimyoviy xossalarga ega. Jismoniy xususiyatlarga zichlik, erish nuqtasi, qaynash nuqtasi, muzlash nuqtasi, rang yoki hid kiradi. Kimyoviy xossalarga misol qilib, elementlarning reaksiyalarda bir-biri bilan birlashishini keltirish mumkin. Element faqat bitta turdagi atomlardan tashkil topgan moddadir. Murakkab ikki yoki undan ortiq kimyoviy bog'langan elementlardan iborat bo'lib, tarkibni aniqlaydigan qat'iy nisbatga ega bo'lgan moddadir. Maxsus jismoniy kuchlar mavjud bo'lganda elementlar va birikmalar bir fazadan ikkinchisiga o'tishi mumkin. Bunday kuchlarning bir misoli haroratdir. Harorat o'zgarganda, faza o'zgarishi mumkin. Siz qaynayotgan suv ustidagi suv bug'ini ko'rishingiz mumkin. Bu bug (yoki gaz) kondensatsiyalanib, suv tomchisiga aylanishi mumkin. Agar siz bu tomchini muzlatgichga qo'ysangiz, u qattiq bo'ladi. Qaysi fazada bo'lishidan qat'i nazar, u hali ham suvdir. U hali ham bir xil kimyoviy xususiyatlarga ega SAVOLLAR: 1. Nima uchun kimyoni o'rganish muhim deb o'ylaysiz? 2. METTER nima? 3. Elektronlar nima? 4. Protonlar nima? MASHQLAR: 1. Men kimman? Quyidagilardan tanlang: elektron, ion, neytron, yadro, proton. a. Men atomning markaziman, menda proton va neytronlar bor. men ... b. Men yadro atrofida harakat qilaman. men ... c. Men ijobiy zaryadlanganman. men ... d. Menda hech qanday to‘lov yo‘q. men ... e. Men elektr zaryadlangan atomman. men ... 2. Savollarni to‘ldirish uchun qanday, qancha, nima, qaysidan foydalaning. a. ... materiyami? b. ... materiya mavjud bo'lishi mumkinmi? c. ... materiyaning uchta holati aniq shaklga egami? d. ... ularning aniq hajmi yo'qmi? e. ... atomlar iboratmi? f. ... atomning tarkibiy qismlari yadrodan tashqarida? g. ... moddalarning xossalari tasniflanadimi? h. ... elementda qanday atomlar mavjud?
