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A-Level Chemistry Paper 1 Definitions Questions and Answers correct Ionic bonding The electrostatic attraction between positive and negative ions Covalent bonding The strong electrostatic force of attraction between a shared pair of electrons and the nuclei of the bonded atoms Dative bonding Where the shared pair of electrons is supplied by one of the atoms only Electronegativity The ability of an atom to attract the bonding electrons in a covalent bond Hydrogen ...

AQA A-level chemistry chemical tests Questions and Answers What is the process for purifying an organic liquid (recrystallisation)? Dissolve impure compound in minimum volume of hot solvent Hot filter solution through (fluted) filter paper quickly Cool the filtered solution by inserting beaker in ice Suction filtrate with a Buchner flask to separate out crystals Wash the crystals with distilled water Dry the crystals between absorbent layer What is the purpose of using the minimum vo...

A-Level Chemistry Paper 1 Definitions Questions and Answers Orbital A region around the nucleus that can hold up to two electrons with opposite spins First Ionisation Energy The energy required to remove 1 mole of electrons from 1 mole of gaseous atoms Ionic bonding The electrostatic attraction between positive and negative ions Covalent bonding The strong electrostatic force of attraction between a shared pair of electrons and the nuclei of the bonded atoms Dati...

AS Level Chemistry Questions and Answers Atomic number Number of protons in an element Mass number Number of protons and neutrons Ion Electrically charged particle formed by the loss/gain of electrons Relative masses of P,N and E 1,1, 1/2000 (respectively) Isotopes Atoms of the same element with different number of neutrons but same number of protons. What are steps of mass spectroscopy? Ionisation, Acceleration, Deflection, Detecting Ionisation ...

AQA A LEVEL Chemistry Questions and Answers Relative atomic mass The average mass of an atom of an element, relative to 1/12th of the mass of an atom of Carbon-12 Relative molecular mass Average mass of a molecule compared to 1/12th of the mass of a carbon-12 atom The Avogradro constant the number of particles in a mole ideal gas equation pV = nRT empirical formula the simplest whole number ratio of atoms of each element in a compound percentage atom econ...

Bio 255 Lab week 5 tests Questions and Answers shoulder bone clavicle upper arm bone humerus thumb side lower arm bone radius pinky side (longer) lower arm bone ulna wrist bone carpals finger bones phalanges on hand ankle bone tarsal toe bones phalanges on foot back of shoulder bone scapula butt bones os coxae upper leg bone clavicle larger lower leg bone tibia smaller lower leg bone fibula w...

Exam 3 Bios 255 Questions and Answers What is the function of the immune reproductive system protects body from infection and fights of pathogen what are the two major defense of immune adaptive and innate non-specific immunity general mechanisms that defend the body against foreign invaders. YOU ARE BORN WITH IT First line of defense skin, mucous membrane, sebum internal defenses: second line of defense inflammation interferon compliment fever phagocytosis ...

Bio 255 exam 2 Questions and Answers The place where two bones meet is called ______. articulation Growth from within cartilage is called ______. interstitial growth Cartilage is what type of tissue? connective In interstitial growth of cartilage ______. news cells and new matrix are produced Chondrocytes occupy small spaces called lacunae Which statements characterize cartilage? It supports soft tissues It provides a gliding surface at joints. It prov...

BIO 255- TEST 2 Questions and Answers Which of the following best describes the direction and function of efferent signals? -away from CNS to cause effect on glands, muscle efferent nervous system somatic sympathetic parasympathetic Autonomic nervous system Parasympathetic pathways Sympathetic pathways Adrenal sympathetic pathways ganglion A location outside of the central nervous system where autonomic signals can synapse -cluster preganglionic autonomic ne...

Bio 255 Lab Week 3 Questions and Answers areolar connective tissue Binds and cushions organs and skin By volume, mostly viscous ground substance Elastic properties from loosely organized protein fibers Highly vascularized adipose tissue Stores triglycerides for a future source of energy (fat cells) Insulation, protects vital organs Only connective tissue with more cells than matrix reticular connective tissue Reticular fibers provide framework (stroma) of organs Found in ...