Atoms: The Building Blocks of Matter
Learning Log
This week in the class of Chemistry, the main focus was Chapter 3, Atoms: The Building Blocks of Matter. There are three laws that was learned in the chapter, like the law of conservation of mass which states that matter is neither created nor destroyed during physical changes or chemical reactions. A chemical compound contains the same elements in exactly the same proportions by mass, regardless of size is called law of definite proportions. The law of multiple proportions is when two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers. The modern atomic theory states that all matter is composed of atoms and that atoms of any one element differ in properties from atoms of another element remain unchanged. From testing cathode rays, two observations were made, 1. Cathode rays were deflected by a magnetic field which was known to have a negative charge, 2. The rays were deflected away from a negatively charged object. Two inferences were made about the atomic structure, which were 1. Because atoms are electrically neutral, they contain a positive charge to balance out the negative electrons, 2. Electrons have very much less mass than atoms, so atoms must contain other particles that account for most of their mass. Rutherford discovered the atomic nucleus after doing his gold foil experiment, and had conclusions about the nucleus. The nucleus is very tiny compared to the atom, it is also very dense and is a packed bundle of matter with positive charge. Nuclear forces are proton or neutron combined forces that hold the nucleus particles together. The atomic number of an element is the number of protons each atom of that element. Isotopes are atoms of the same element that have different masses. The mass number is the total number of protons and neutrons that make up the nucleus of an isotope. The average atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of an element. The Avogadro number is the number of particles in exactly one mole of a pure substance, 6.022X10^23. The mass of one mole of a pure substance is called the molar mass.
Lab Abstract
This week in Chemistry, the main purpose of the lab was to determine how the levels of the salt changed by heating the crucible it was in. The other purpose that is important is to get the water out of the salt. The group of students had to record the weight of the salt without water in it and with water in it. Students wore lab coats and eye protection because of possible burning and the crucible was very hot, in which students used prongs to handle with it. From the conclusions that were gathered, the measurements of the students were very close to the exact number at the end of the lab. To improve this lab, students have to use more precise measurements to further get more closer to the exact results.
Learning Log
This week in the class of Chemistry, the main focus was Chapter 3, Atoms: The Building Blocks of Matter. There are three laws that was learned in the chapter, like the law of conservation of mass which states that matter is neither created nor destroyed during physical changes or chemical reactions. A chemical compound contains the same elements in exactly the same proportions by mass, regardless of size is called law of definite proportions. The law of multiple proportions is when two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers. The modern atomic theory states that all matter is composed of atoms and that atoms of any one element differ in properties from atoms of another element remain unchanged. From testing cathode rays, two observations were made, 1. Cathode rays were deflected by a magnetic field which was known to have a negative charge, 2. The rays were deflected away from a negatively charged object. Two inferences were made about the atomic structure, which were 1. Because atoms are electrically neutral, they contain a positive charge to balance out the negative electrons, 2. Electrons have very much less mass than atoms, so atoms must contain other particles that account for most of their mass. Rutherford discovered the atomic nucleus after doing his gold foil experiment, and had conclusions about the nucleus. The nucleus is very tiny compared to the atom, it is also very dense and is a packed bundle of matter with positive charge. Nuclear forces are proton or neutron combined forces that hold the nucleus particles together. The atomic number of an element is the number of protons each atom of that element. Isotopes are atoms of the same element that have different masses. The mass number is the total number of protons and neutrons that make up the nucleus of an isotope. The average atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of an element. The Avogadro number is the number of particles in exactly one mole of a pure substance, 6.022X10^23. The mass of one mole of a pure substance is called the molar mass.
Lab Abstract
This week in Chemistry, the main purpose of the lab was to determine how the levels of the salt changed by heating the crucible it was in. The other purpose that is important is to get the water out of the salt. The group of students had to record the weight of the salt without water in it and with water in it. Students wore lab coats and eye protection because of possible burning and the crucible was very hot, in which students used prongs to handle with it. From the conclusions that were gathered, the measurements of the students were very close to the exact number at the end of the lab. To improve this lab, students have to use more precise measurements to further get more closer to the exact results.