Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Uddingston Grammar School National 5 Chemistry Atomic Structure and Bonding Unit 1 sub-unit b.1 Homework 3 1. An element has an atomic number of 11 and a mass number of 23. The number of electrons present in an atom of this element is? A B C D 11 12 23 34 (1) 2. Which line in the table correctly describes a neutron? A B C D Mass 1 Negligible 1 1 Charge -1 0 +1 0 (1) 3. Which of the following is the electron arrangement of sodium metal? A B C D 2,8,1 2,8,2 2,8,7 2,8,8 (1) 4. Isotopes of the same element have identical A B C D nuclei mass number number of neutrons number of protons (1) 5. An atom has 26 protons, 26 electrons and 30 neutrons. The atom has A B C D atomic atomic atomic atomic number number number number 26, 56, 30, 52, mass number mass number mass number mass number 56 30 26 56 (1) 6. The table shows the numbers of protons, electrons and neutrons in four particles, W, X, Y and Z. Which pair of particles are isotopes? A B C D W and X W and Y X and Y Y and Z (1) 7. Sodium has 10 electrons. (a) Complete the diagram to show how the electrons are arranged. You may wish to use the data booklet to help you. (1) (b) Explain what holds the negatively charged electrons in place around the nucleus. (1) 8. The Group 7 element bromine was discovered by Balard in 1826. Bromine gets its name from the Greek ‘bromos’ meaning stench. Bromine consists of a mixture of two isotopes 79Br and 81Br. (a) What is meant by the term isotope? (b) Complete the table for Isotope (1) 79Br. (1) Number of protons Number of neutrons 79Br 35 (c) The relative atomic mass of an element can be calculated using the formula: A sample of bromine contains 55% of the isotope with mass 79 and 45% of the isotope with mass 81. Calculate the relative atomic mass of bromine in this sample. (2) 9. Which line in the table correctly describes an electron? A B C D Mass Charge negligible negligible 1 1 +1 –1 +1 0 (1) 10. In the manufacture of glass, other chemicals can be added to alter the properties of the glass. The element boron can be added to glass to make ovenproof dishes. (a) Information about an atom of boron is given in the table below. Particle proton neutron Number 5 6 Use this information to write the nuclide notation for this atom of boron. (1) (b) Atoms of boron exist which have the same number of protons but a different number of neutrons. What name can be used to describe these different types of boron atoms? (1)