Bohr atomic model Study guides, Class notes & Summaries

CLEP Chemistry Latest Update Graded A John Dalton Proposed that matter is composed of atoms; these atoms have different identities called elements, which combine to form compounds; measured masses of reactants and products. J.J. Thompson Observed deflection of particles in a cathode ray tube; proposed that atoms are composed of positive and negative charges; developed the plum pudding model of the atom Robert Millikan Calculated the charge-to-mass ratio of electrons using oil drops falling in ...

GCSE Combined Science Edexcel Physics – Paper 1 Foundation Tier Predicted Paper 2023 attached with correct marking scheme Name …………………………………………………………………… Date ………………… 1 hour 15 minutes allowed. You may use a calculator and an Edexcel equation sheet. Grade boundaries These are VERY rough guesses! Getting a 4 on this paper does not guarantee you the same mark in the exam. • 5-5 60% • 4-4 50% • ...

DAT General Chemistry Exam |170|questions with complete solution Atomic Number ANS-number of protons found in that atom; low number; (Z) Mass Number ANS-Protons + Neutrons; high number; (A) Atomic Mass ANS-relative mass of that atom compared to the mass of a carbon-12 atom (which is set at 12.00); measured in amu; 1 amu = ANS-1.66x10^-24 Atomic Weight ANS-weight (g) of one mole (mol) of a given element (g/mol); the weighted average of all the masses (not the weights) of an element, ...

IB Chemistry Unit 2 SL Latest Version Rated A+ Emission spectrum An emission spectrum is produced when an atom moves from a higher to a lower level. The line emission spectrum of hydrogen provides evidence for __________________ which converge at _____________ The line emission spectrum of hydrogen provides evidence for the existence of electrons in discrete energy levels which converge at higher energies. Continuous spectrum All the colours / wavelengths present merge smoothly in...

AQA AS Physical Chemistry 2024 exam questions with 100% correct answers Who described atoms as solid spheres that make up different elements and when? - ANSWERS John Dalton in the 19th century Who suggested that atoms of a particular element had the same mass and atoms of different elements had different masses and when? - ANSWERS John Dalton in 1803 Who discovered the electron and when? - ANSWERS JJ Thomson, 1897 discovered electrons proving atoms weren't indivisible or solid. New m...

OCR 2023 GCSE Combined Science Physics A Gateway Science J250/11: Paper 11 (Higher Tier) Question Paper & Mark Scheme (Merged) COMBINED SCIENCE PHYSICS A Please write clearly in black ink. Do not write in the barcodes. Centre number Candidate number First name(s) Last name Oxford Cambridge and RSA Thursday 25 May 2023 – Morning GCSE (9–1) Combined Science A (Physics) (Gateway Science) J250/11 Paper 11 (Higher Tier) Time allowed: 1 hour 10 minutes INSTRUCTIONS • Use blac...

AQA AS Physical Chemistry 2024 Exam Questions And Answers Who described atoms as solid spheres that make up different elements and when? - ANSWER- John Dalton in the 19th century Who suggested that atoms of a particular element had the same mass and atoms of different elements had different masses and when? - ANSWER- John Dalton in 1803 Who discovered the electron and when? - ANSWER- JJ Thomson, 1897 discovered electrons proving atoms weren't indivisible or solid. New model named pl...

AQA AS Physical Chemistry 2024 exam questions with 100% correct answers Who described atoms as solid spheres that make up different elements and when? - ANSWERS John Dalton in the 19th century Who suggested that atoms of a particular element had the same mass and atoms of different elements had different masses and when? - ANSWERS John Dalton in 1803 Who discovered the electron and when? - ANSWERS JJ Thomson, 1897 discovered electrons proving atoms weren't indivisible or solid. New m...

GCSE EDEXCEL TRIPLE SCIENCE CHEMISTRY PAPER 2 2024/2025 QUESTION PAPER ALREADY PASSED What does 'aq' mean? - answer Aqueous - it is dissolved in water Water - formula - answer H20 Ammonia - formula - answer NH3 Carbon Dioxide - formula - answer CO2 Hydrogen - formula - answer H2 Chlorine - formula - answer Cl2 Oxygen - formula - answer O2 Ammonium (ion) - formula - answer NH4 (+) Hydroxide (ion) - formula - answer OH (-) Nitrate (ion) - formula - answer NO3 (-) Carbonate (ion) -...

AQA 2023 AS CHEMISTRY 7404/2 Paper 2 Organic and Physical Chemistry questions and answers verified What is the equation linking mass moles and MR? Mass=moles * MR What is the definition of Ar (relative atomic mass)? The average mass of an atom of an element compared to the mass of one twelfth of carbon 12. What does Mr stand for? Relative molecular mass Define relative isotopic mass. The mass of an isotope of an element compared to the mass of one twelfth of the mass of carbon 12 ...