The center-most part of an atom where the protons and neutrons 5. The weighted average mass of an element’s isotopes of that element 4. The smallest particle of an element that retains the properties 3. High-energy radiation that has no charge and no mass of neutrons 2. Atoms with the same number of protons but different numbers 1.
HSC Chemistry Assessment task 1 Nuclear Chemistry Research report 1. Distinguish between stable and radioactive isotopes and describe the conditions which a nucleus is unstable. To understand if an element is stable we first must understand what stability is. The stability of the nucleus is directly related to the strength of the forces that hold the nuclear particles together. These protons and neutrons of the nucleus are called nucleons.
Column 17 is made up of the more reactive gases- the halogens. The noble gases are in column 18. The electrons are the most significant part of an atom. When atoms don’t have the sufficient number of electrons they need in their outer level, they will do whatever they can to get the number they need. The number of protons an atom has is its atomic number.
Name___________________________________ periodic table review 3 12/5/2006 Page 1 Key Terms 1. What is the name of the family of elements in Group IA/1? a. alkali metals b. alkaline earth metals c. halogens d. noble gases e. none of the above 2. What is the name of the family of elements in Group IIA/2? a. alkali metals b. alkaline earth metals c. halogens d. noble gases e. none of the above 3.
(1 point for each molecule) The central atom is C. 2. How many atoms are bonded to the central atom? (1 point for each molecule) There are two atoms bonded to the central atom. 3. How many lone pairs of electrons are on the central atom?
Which of the following is a trace element that is required by humans and other vertebrates? A) nitrogen B) calcium C) iodine D) sodium E) phosphorus 3) Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus? A) atomic mass B) atomic weight C) atomic number D) mass weight E) mass number 4) Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must
Which pairs will react from an ionic compound? Chlorine and oxygen Nitrogen and Lithium b. Which pairs will react from a molecular compound? Flour nine and Argon c. Which pairs will not react to form a compound? Aluminium and potassium 7) A certain particle was found to contain sixteen protons and eighteen electrons.
Your friend says that what makes one element distinct from another is the number of electrons about the atomic nucleus. Do you agree wholeheartedly, partially, or not at all? Explained • NO • What makes one element distinct from another is the number of protons in the nucleus. Hydrogen has 1, gold has 79, uranium has 92, etc. Not electrons.
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.
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.