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Science Homework week 2 1.Identify which of the three sub atomic particles (p+, n, e–): P+: Positive charge e-: spin around the nucleus, are the smallest, negative n: neutral, 2. in figure 1.1.1 there are two protons and neutrons with two electrons spinning around the outside. 3. Explain the relationship between the number of protons and electrons in an atom. The relationship between the protons and electrons are that they are both opposite charge and they balance so that they don’t spin out of the atom. 4. Clarify the following expressions. a: atomic number= number of protons=number of electrons b: mass number= number of protons+ number of neutrons c: nucleus= 5. Fe 2656 Protons: 56 Neutrons: 30 Electrons: 56 Ni 28 59 Protons: 59 Neutrons: 31 Electrons:59 Cu 29 64 Protons: 64 Neutrons: 35 Electrons: 64 Au 197 79 Protons: 79 Neutrons: 118 Electrons: 79 6. What information would you use to distinguish between atoms of different elements? The numbers of protons, neutrons and electrons. 7. Use an example to identify the smallest unit of an element. 8 a. Dalton proposed his atomic theory in 1808. Outline the theory. All matter is composed of atoms, Atoms cannot be made or destroyed, All atoms of the same element are identical, Different elements have different types of atoms and Chemical reactions occur when atoms are rearranged b. Explain which part of Dalton’s atomic theory was later found to be incorrect. All atoms of an element are identical and have the same properties and atoms consisted of at least two smaller parts, unlike Dalton's idea that atoms are indivisible. 9. Use examples to distinguish between atoms and molecules. Molecules are a structure of number of atoms that join to create a substance for example, water or h2o, which is a combination of one hydrogen atom and two oxygen atoms. 19. State the elements, and how many there are of each, in a single molecule of: a SO2 b H2S c C12H22O11 d H2SO4 e CH3COOH (takecare!)