...What are Atoms? Electromagnetism How Much Electricity Do We Use Everything is made of atoms. Even you and I are made of atoms. Atoms are the building blocks of the universe. They are very, very tiny particles. Their size is very hard to imagine. An atom is best described by thinking of the sun with the planets spinning around it. The centre is called the nucleus. It is made of tiny particles called protons and neutrons. Electrons circle around the nucleus in clouds, or shells, far from the nucleus. When an atom is in balance, it has the same number of protons and electrons. It can have a different number of neutrons. Electrons stay in their shells because a special force holds them there. Protons and electrons are attracted to each other. We say protons have a positive charge (+) and the electrons have a negative charge (-). Opposite charges attract each other. Have you ever combed your hair and had it follow the comb or have you ever rubbed a balloon over your head and have your hair stand straight up on your head? If so, you rubbed electrons off the comb or balloon. The electrons moved into your hair from the comb or balloon. They tried to get far away from each other. They moved to the ends of your hair. They pushed against each other and made your hair move - they repelled each other or pushed each other away. The electrons near the nucleus are held tight to the atom while sometimes the ones further out are not. These electrons can be made to move out of their...
Words: 350 - Pages: 2
...Everybody Atom opened the doors of Lionel’s Law Firm on his way home after a long day at work. He strolled down the sidewalk looking around at the many different faces of the city of New York. He noticed how people look different, have different cultures, have different clothes, and personalities, and thought about how different people were. As Atom was daydreaming he felt his phone vibrate in his pocket. He looked at his phone and it read Ashley, his wife. He answered the phone. He continued walking home as his wife argued with him on the phone. He stepped to a curb, half looked for cars, and began walking across the street. A car came flying by and hit him, he then flew 30 feet into a building and died. “Woah, where am I?” Atom said as he awoke in all white...
Words: 1210 - Pages: 5
...Three or four of the following statements are true and correct. Which one, if any, is false? If all the statements are true, choose answer E. A) Carbon, hydrogen, oxygen, and nitrogen make up approximately 96% of living matter. B) The trace element iodine is required only in very small quantities by vertebrates. C) Virtually all organisms require the same elements in the same quantities. D) Iron is an example of an element needed by all organisms. E) All of the other statements are true and correct. Answer: C Topic: Concept 2.1 Skill: Knowledge/Comprehension 4) Which of the following statements is false? A) Atoms of the various elements differ in their number of subatomic particles. B) All atoms of a particular element have the same number of protons in their nuclei. C) The neutrons and protons present in the nucleus of an atom are almost identical in mass; each has a mass of about 1 dalton. D) An atom is the smallest unit of an element that still retains the properties of the element. E) Protons and electrons are electrically charged particles. Protons have one unit of negative...
Words: 4607 - Pages: 19
...Name Lab Section Date The Mole Concept and Atomic Weights Text Reference: Tro, Chemistry: Structure and Properties Section 2.8 - Atoms and the Mole: How Many Particles? Section 1.9 – Atomic Mass: The Average of an Element’s Atoms The purpose of this activity is to better understand the concepts of relative atomic mass, counting by weighing and the mole. Per cent composition and average atomic mass are included. Part I. Relative Atomic Masses and the Mole – Early Method When John Dalton proposed his atomic theory, he stated that the atoms of each element had a characteristic mass. He carried out experiments to determine the relative atomic mass of each element. To do this, he had to establish a standard because a single atom was too small to weigh. The standard he chose was that the mass of hydrogen would be set equal to 1.000. In a simple experiment, Dalton would measure the grams of an element such as sulfur that reacted with 1.00 gram of hydrogen. For sulfur, the reacting mass was found to be 32.0 grams, and so 32.0 was the relative mass of sulfur with respect to the standard hydrogen. (Note: The current standard for atomic mass is the most abundant isotope of carbon, C-12, with an assigned mass of exactly 12.000 amu.) The following activity will demonstrate how the relative mass method works. 1. Weigh five of the red color balls to three decimal places. Be sure to tare out the mass of the plastic cup. Record the mass in the table below. 2. Weigh five...
Words: 1665 - Pages: 7
...you is made of atoms – atoms and their chemical combinations, molecules. Everything you can see, touch, smell, and taste is made up of chemicals. So, the science of chemistry is a very wide ranging science. Parts can concentrate on how interactions of atoms and molecules allow the nerves in your body to conduct electrical signals. Other parts might concentrate on analyzing clues left by a burglar in order to help the police solve a crime. Still, other parts of chemistry might be involved in making new polymers that might be used by the fashion industry to make more colorful and longer wearing fabrics. If you have access to a computer and the internet, there are a number of excellent tutoring sites to help students gain a better understanding of chemistry. One of the better sites for middle school students Is: www.chem4kids.com/ This site is written at middle school level and has a number of on-line tests that you can use to check your understanding of the material. Several other good internet sites are: http://chemistry.about.com/od/chemistry101/Chemistry_101_Introduction_to_Chemistry.html - Chemistry 101 - a collection of articles and on-line help sites in chemistry http://library.thinkquest.org/10429/low/indexl.htm - ChemWeb on line - an introductory chemistry course on line http://library.thinkquest.org/2923/ - Chemistry Tutor – on line help for chemistry So, let’s get started. If you want to review chemistry for 8th grade, let’s consider what you will need...
Words: 5393 - Pages: 22
...you describe the periodic nature and properties of atoms and molecules. Explain at a level of detail Dmitri Mendeleev would have understood how halogens and alkali metals are extremely reactive, whereas noble gases are not reactive. Compare properties of molecules formed from atoms in similar families; for example, H2S versus H2O. Explain what is meant by the electronic structure of atoms. How does knowing the electronic structure of atoms aid chemists in predicting chemical reactions? Periodic Table is designed to help us understand how elements are going to react to each other and also gives us the breakdown of how many atoms are in each element. This chart also helps us to identify metals, liquids, and gases. This chart shows us the atomic mass and structure of each element. Knowing this information allows us to determine which elements can bond and interact with each other. Alkali metals and halogens can form ionic bonds easily which involves the transfer of an electron from an atom of metal forming a positively charged species, to an atom of non-metal forming a negatively charged species. These two species interact electrostatically and form one of the two extreme forms of bonding; covalent bonding is the other extreme form (Kostiner & Jespersen, 2003). Electronic structure is another piece of important information that you will find on the Periodical Table, this is the atomic number and it will tell you how many atoms make up the element. Alkali Metals and Halogen We...
Words: 1056 - Pages: 5
...64 Practice Problems – Chapter 14 – Chem 1C 1. Which of the following molecules contains a nitrogen atom that is sp2 hybridized? A) NH3 B) NO3- C) N2 D) HCN E) C2N2 2. Consider the structure of glycine, the simplest amino acid: What is the total number of bonds in the molecule? A) 0 B) 1/2 C) 1 D) 2 E) More information is needed. 3. What is the hybridization of I in the molecule ICl3? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 4. What is the hybridization of S in the molecule H2S? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 5. What is the hybridization of C in the ion CN-? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 6. Atoms that are sp3 hybridized form ____ pi bond(s). A) 0 B) 1 C) 2 D) 3 E) 4 7. What is the hybridization of the central atom in SF6? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 8. What is the hybridization of the central atom in PCl4+? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 9. What is the hybridization of the central atom in IF5? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 10. What is the hybridization of the central atom in SF4? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 11. What is the hybridization of O in OF2? A) sp B) sp2 C) sp3 D) dsp3 E) d2sp3 12. Consider the following molecule. (Lone pairs are not drawn in.) Specify the hybridization of each carbon atom (in numeric order: C-1 C-2 C-3 C-4 C-5). A) sp2 sp2 sp2 sp3 sp B) sp2 sp2 sp2 sp3 sp3 ...
Words: 2346 - Pages: 10
...What is a molecule? Well, simply put it's just a group of atoms bonded together. However, there are special molecules; these are polar and nonpolar molecules. Molecules make us up, they are made up of atoms. Which have electrons, electrons are little balls with a negative charge, and like magnets opposite attract. This brings us to electronegativity. Electronegativity is a measure of the tendency towards an atom to attract a bonding pair of electrons. What is a polar molecule? Simply put, it's a particle that has two or more covalently bonded atoms. (A covalent bond is a bond where two atoms share their electrons to become stable ) With an asymmetric distribution of changes, this occurs to molecules that are asymmetric along at least one axis....
Words: 414 - Pages: 2
...Neutrons, Electrons and still other particles that are smaller than atoms are called subatomic particles. Proton, Neutrons are located at the center of an atom. The electrons are in motion at some distance from the nucleus. 2. Does the law of definite proportions apply to mixtures? Explain. Yes. This idea to apply to all matter – gases, solids and liquids 3. Does the law of definite proportions apply to elements? Explain No. because this law definite proportions or definite compositions applies to all pure compounds. And element cannot be decomposed 4. Name the three scientific laws that provided the basic evidence for Dalton’s atomic theory * The law of multiple proportions * The law of definite proportions * The law of multiple 5. State briefly the four basic principles of Dalton’s atomic theory. * All elements are composed of atoms, which are indivisible and indestructible particles. * All atoms of the same elements are exactly alike; in particular, they have the same mass * All atoms of different elements are different; in particular they have different masses * Compounds are formed by the joining of atoms of two or more elements. In compounds, the atoms of the different elements in the compound are joined in a definite whole – number ratio such as 1:1, 2:1, or 3:2 6. Describe the three major changes made in Dalton’s atomic theory in order to make it satisfactory today. * Atoms are not indivisible. They are made up of smaller particles-...
Words: 904 - Pages: 4
...are composed of atoms rather we can see them or not. Some elements are bonded with a variety of atoms to help form the molecules. All matter is made up of atoms that are very small, so small that they human eye cannot see. It does not matter if the liquid, solid, or gas even if it is a mixture or pure. These basic elements are the same elements that make up what is known as the periodic table. Mendeleev Demetri Mendeleev created the periodic table and was trying to put the elements in order by the weight that he saw. As the weights grew from time to time the attributes of one element may be similar to those Mendeleev listed. So Mendeleev would put the elements in a column that were alike chemically (Tro, 2009). All chemicals in the vertical rows of the periodic table were considered to be family because the attributes were a lot alike. In group 1A of the table of elements are the alkali metals, in column 7A are the halogens (Tro, 2009). Noble gases are in the column of 8A, the noble gases are in this specific column because they are gases that are unreactive because the shell has being closed. So because of similarities Mendeleev built has table of elements based on similarities. Atoms Atoms are considered the smallest existence that has similar attributes of an element, but the atom cannot be broken down into a smaller part. The formation of molecules happens when two or more atoms are put together, which can happen in many different ways. When two atoms of oxygen are put...
Words: 688 - Pages: 3
...structure of the atom changed over time? The idea of an atom was first conceived by the ancient philosophers of Greece. In the fifth century BC, Leucippus and his student Democritus suggested that there were small indivisible particles, which he called atoms – from the Greek atomos meaning ‘uncuttable’. This idea of atoms has been built on by many other scientists over hundreds of years. These scientists have drawn conclusions from a variety of different experiments. Some conclusions have been arrived at when scientists were researching other questions, and some ideas have been proven by designing a specific experiment. A model of the structure of the atom is still evolving today. Particle physicists are working at particle accelerators like CERN, on newly discovered quarks. In this task you will be researching one of the models to have been developed over the years to describe the structure of an atom. Task Your task is to produce a report into one of the different models of the atom that has been developed by scientists since 1890. Your research should be done online, using the web links provided below as well as any other credible sources you feel would be useful. Your report will be a written report and should include images and, where appropriate, diagrams of the experiments conducted. Your report should include: * Information about the key scientists who developed this model of the atom * A description of what they believed the atom looked like when...
Words: 849 - Pages: 4
...Crystal Structures The regular geometric shapes of crystals reflect the orderly arrangement of the atoms, ions, or molecules that make up the crystal lattice. Many different types of compounds will form crystals when solid; metals and ionic compounds are almost always in solid crystal form at room temperature. Only a few covalently bonded compounds are solids at room temperature. Of those covalent compounds that are solid, not all form crystals. The ones that do not are referred to as amorphous. Many covalently bonded compounds which are liquids or gases at room temperature will crystallize at lower temperatures (i.e. water forming ice). In this experiment, you will be using styrofoam spheres as models of atoms or ions to gain insight into the ways in which metallic or ionic crystals are formed. You will investigate three basic crystal structures which can form if all of the particles are the same size, as would happen in a pure metal: simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC). structures. Using the styrofoam models, you will determine the number of nearest neighbors (the coordination number) of the particles in each of these structures. In a simple crystal structure, all atoms or ions of the same type should have the same coordination number; in other words, any atom or ion of the same element is identical with respect to size and position relative to its neighbors. When ions form crystals, the cations and anions are...
Words: 1802 - Pages: 8
...of discrete units called atoms. Here we will see the views of what makes up atoms, two great philosophers, compare, and contrast their views on the atomic theory and what it is. Let us first look at one of the greatest ancient philosopher of atomism, Democritus, also known as the laughing philosopher 460 – 370 BC. Democritus stated that all matter is made of units that move around in a void. The purpose of this void is for atoms to change motion from place to place through the void moving in a senseless motion colliding with each other. He also stated that the void had an equal right with reality, is to considered existent. He conceived of the void as a vacuum, an infinite space in which moved an infinite number of atoms that make up the physical world. The combinations of atomic formed by creation growth and destruction. These atoms are absolutely small that their size cannot be seen by the senses. Democritus had that the view that all matter being atoms, he believed persons saw changes in things because of the rearrangement of atoms and earth, fire, air and water were also atoms. Although these matters are made up of the same matter, they differ in shape, size, position and arrangement; they are even indivisible, completely solid, unchangeable, and indestructible and weigh no weight. These ever moving atoms have no qualities but position and the common stuffs and qualities of our senses are apperances of the various shapes and combination of atoms. Thus, white things have...
Words: 821 - Pages: 4
...describe the structure and size of an atom. How big is the nucleus in comparison to the entire atom? Atoms are extremely small; millions of atoms could fit end to end across a period at the end of a sentence. Protons and neutrons are found in the tiny nucleus at the center of the atom. The rest of the atom’s volume is made up of electrons, which surround the nucleus. The nucleus is very small compared to the atom as a whole, but it contains a majority of the atom’s mass. 7. What determines an atom’s atomic number? What determines its atomic mass number? Under what conditions are two atoms different isotopes of the same element? What is a molecule? The atomic number is the number of protons in a chemical element’s nucleus. The atomic mass number is the combined number of protons and neutrons in an atom. Isotopes occur when versions of an element have the same number of protons but a different number of neutrons. A molecule is formed when atoms of the same element combine. 8. What is electrical charge? Will an electron and a proton attract or repel each other? Will two elections attract or repel each other? Explain. Electrical charge is a fundamental property that describes how strongly an object will interact in electromagnetic fields. Protons and electrons attract each other, but two electrons repel. Protons have a positive charge and electrons have a negative charge; like charges repel one another, but opposite charges attract. 10. What do we mean when we say that energy...
Words: 1087 - Pages: 5
...once to complete the passage. covalent bond molecule sigma bond exothermic pi bond When sharing of electrons occurs, the attachment between atoms that results is called a(n) (1) . When such an attachment is formed, bond dissociation energy is released, and the process is (2) . When two or more atoms bond by means of electron sharing, the resulting particle is called a(n) (3) . If the electrons shared are centered between the two atoms, the attachment is called a(n) (4) . If the sharing involves the overlap of parallel orbitals, the attachment is called a(n) (5) . In your textbook, read about single and multiple bonds and bond strength. Circle the letter of the choice that best completes the statement or answers the question. 6. In what form do elements such as hydrogen, nitrogen, and oxygen normally occur? a. as single atoms c. as molecules containing three atoms b. as molecules containing two atoms d. as molecules containing four atoms 7. How many electrons are shared in a double covalent bond? c. none b. one c. two d. four 8. Bond length is the distance between d. two molecules of the same substance. c. the nuclei of two attached atoms. e. the electrons in two attached atoms. d. the orbitals of two attached atoms. 9. Which of the following relationships relating to bond length is generally correct? f. the shorter the bond, the stronger the bond ...
Words: 916 - Pages: 4
