Subatomic Particles and the periodic table 1. The three particles and their properties An atom has no overall charge. The protons (positively charged) and neutrons (no charge) make up the nucleus of an atom, and this is surrounded by negatively charged electrons. There are as many protons as electrons, so they balance each other out, creating a neutral relative charge on the atom. Neutrons, Protons and electrons are all sub-atomic particles.
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.
Because its density is so high, neutrons spin in the same way that electrons do so must obey the Pauli Exclusion Principle. 6. A pulsar does not pulse, it emits beams of radiation that sweep around the sky as the neutron star rotates, and astronomers detect pulses when they sweep over the Earth. 11. Sometimes in binary systems, mass flows into a hot accretion disk around the neutron star and causes the emission of x rays.
With the exception of gravity, electromagnetic phenomena as described by quantum electrodynamics account for almost all physical phenomena observable to the human senses, including light and other electromagnetic radiation, all of chemistry, most of mechanics (excepting gravitation), and, of course, magnetism and electricity. Electromagnetic fields are time varying fields containing both electric fields and magnetic that feed upon each other even in a vacuum. A vacuum is defined as a void of medium. These field lines actually detatch themselves from the source and can exist on
1 AU b. 149,600,000 km c. 8.3 light-minutes d. all of the above 5. Distances between stars are usually measured in a. light-minutes b. astronomical units c. light-days d. light-years 6. Einstein developed an equation that changed ideas about the sun’s energy source by describing the relationship between a. mass and energy b. gravity
The electrons of an atom are bound to the nucleus by the electromagnetic force. A group of atoms can remain bound to each other by chemical bonds based on the same force, forming a molecule. An atom containing an equal number of protons and electrons is neutral; otherwise it is positively or negatively charged and is known as an ion. An atom is classified according to the number of protons and neutrons in its nucleus the number of protons controls the element, and the number of neutrons determines the isotope of the element. A molecule is an electrically neutral group of two or more atoms held together by chemical bonds Molecules are recognized from ions by their lack of
A molecule in which the central atom forms three single bonds and has one lone pair is said to have a ________ shape. A) bent B) linear C) planar D) pyramidal E) tetrahedral 8. A bond where the electrons are shared equally is called a(an) ________ bond. A) polar covalent B) coordinate covalent C) nonpolar covalent D) ionic E) none of the above 9. In a precipitation reaction the insoluble product can be identified by the symbol ________.
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
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.