* c. If you were to place elements X and Y into the periodic table, would element Y be in the same period as element X? If not in the same period, where might they be relative to each other in the periodic table? * Yes, they would be in the same period since they show the similar ionization energy trends. * d. Would an atom of Y be smaller or larger than an atom of X? Explain your reasoning.
Describe the differences between protons and electrons The difference between protons and electrons is that protons are positively charged and that elections are negatively charged. Another difference is that protons are in the nucleus and electrons circle the nucleus in shells outside the nucleus. What is the difference between the mass number and the relative atomic mass of an element? The difference between the mass number and the atomic mass is that the mass number is the number of protons and neutrons in the nucleus and the relative atomic mass is the mass of an atom. Distinguish between an element and a compound with 2 examples for each An element is a substance that cannot be broken down into any simpler substances.
These added together make the relative atomic mass. The mass number displayed on the periodic table, however, is only an average number, as there are many different isotopes if the same atom. The mass of the atom determines the weight of the atom, and the elements are ordered by the mass
The atomic masses of two isotopes of cobalt are 59 and 60. a) What is the number of protons and neutrons in each? • The protons are the same otherwise it wouldn't be cobalt = 27 So the remainders are neutrons = 32 or 33 b) What is the number of orbiting electrons in each when the isotopes are electrically neutral? • Electrons = protons = 27, if electrically
OCR B CHEMISTRY F331 (Unit 1) Revision Guide 2014 Formulae, equations and amount of substance | Key Terms (a). * Atomic Number: Atomic number is the number of protons in the nucleus. * Mass Number: Mass number is defined as the sum of the numbers of protons and neutrons in the atom’s nucleus. * Isotopes: Atoms with the same number of protons but different number of neutrons are called isotopes; they therefore have different masses. * Avogadro’s constant: The number of toms per mole is called the Avogadro’s constant.
David Kemp OCR Chemistry A Unit 1: F321 Atomic Structure (a) describe protons, neutrons and electrons in terms of relative charge and relative mass; Proton +1 1 Neutron 0 1 Electron -1 1/2000 Relative Charge Relative Mass (b) describe the distribution of mass and charge Within an atom; Positively charged Nucleus containing most of the mass, surrounded by atomic shells with orbiting electrons of negative charge and negligible mass. (c) describe the contribution of protons and neutrons to the nucleus of an atom, in terms of atomic (proton) number and mass (nucleon) number. The atomic number of the nucleus, also the proton number, shows the number of protons in the nucleus. It also defines the element. The number of neutrons added to the number of protons is the nucleon number or mass number.
Using the same electronic balance, the average mass of five copper slugs, in grams, will be determined. Lastly, by using the electronic balance again, the weight of two different unknown weights, in grams, will be determined by the weighing by difference method. Using both the direct weight and weighing by difference techniques, the weight of the copper slug (2.98 g) and the two unknown weights can be fairly accurately determined using the centigram balance. However, since the electronic balance can determine mass out to three decimal places, the electronic balance was more accurate weighing the copper slug (3.022 g) than the centigram balance using the direct weight and weighing by difference methods. Determining the mass of the two unknown weights (unknown weight #1 and #2) was determined using only the centigram balance using the weighing by difference method.
Empirical formula: CH5N Steps for molecular formula: 1- Calculate the molar mass of the empirical formula. 2- Divide the known (given) molar mass by the calculated empirical formula molar mass to get a whole number 3- Multiply that whole number through subscripts of the empirical formula to obtain the molecular formula. Example CH5N 12.01 g C x 1 C= 12.01 g/mol 1.008 g H x 5 H = 5.040
If the atom is alone, such as the iron on the left and the hydrogen on the right, you can just multiply that atom. To start the process, we would need to put a three in front of the H2O on the left, to get three oxygen atoms. But, keep in mind this also will give you six hydrogen atoms. (Two times the three.) This will bring your equation to look like this: 3H2O+Fe ---> FeO3+H2 The equation is not yet balanced, since we now have an uneven number of iron and hydrogen atoms.
Nuclear fussion: Nuclear fusion is the process in which two light nuclei combine to form a heavier nucleus. The total masses of the products are less than the combined mass of the two light nuclei. The energy equivalent of the loss of mass is released. The release of energy during nuclear fusion can also be calculated from the values of the