CIDESCO QUESTIONS (Natural sciences portion) Questions with correct Answers 2023

CIDESCO QUESTIONS (Natural sciences portion) Questions with correct Answers 2023 which ones are correct? 1. Biological and non-biological substances both need oxygen for their existence 2. the human body consists only of biological substances 1 and 2 are both correct which ones are correct? 1. every living organism needs some non-biological substances for its existence 2. all non-biological substances are found as minerals in the earth 1 is correct 2 is incorrect characteristics of life include.. growth and metabolism examples of synthetic substances are... plastics and silicones examples of organic biological substances are carbohydrates and fats examples of mineral substances are paraffins and petroleum matter is everything that... occupies space and has weight the three forms of matter are solids, liquids, and... gases what property does all matter have? all matter has weight condensation is the change of matter from... gas to liquid vaporization is the change of matter from.. liquid to gas melting is the change of matter from a solid to a liquid sublimation is the change of matter from a solid to a gas the alteration of the prorates of matter without the formation of any new substance is called. a physical change the immediate change of a solid into a vapor is called sublimation an example of a single-celled cellular organism is a bacterium which ones are correct? 1. a micro-organism is the smallest part of the human body 2. all micro-organisms need nutrients for their existence 1 is incorrect and 2 is correct examples of bacteria are bacilli and cocci science deals mainly with... physics and chemistry the study of structure of the body is called anatomy the study of the functions of living organisms is physiology which is correct? 1. anatomy is a very important science in the field of biology 2. anatomy is the science which deals with the functions of the human body 1 is correct and 2 is incorrect which science does the alteration of the structure of molecules belong to? Chemistry the field of physics includes heat and electricity an Anion is a negatively charged atom A cation is a positively charged atom an electrolyte is a substance that when dissolved in water splits into ions examples of electrolytes are acids and salts an example of an electrolyte is a salt solution an acid is an electrolyte because it can conduct electric current an example of an inorganic acid is sulphuric acid an alkali must contain metal atoms and hydroxyl groups (OH) an example of an alkaline substance is soap if a metal-oxide is dissolved in water it forms an alkali pH can be decreased by increasing hydrogen-ions the letter p in pH means potential pH is... the number of free H-ions in a solution if the pH of a solution is between 5 and 7, the solution is a weak acid if the pH of a solution is between 1 and 3, the solution is a strong acid if the pH of a solution is between 7 and 9 the solution is a weak alkali if the pH of a solution is between 12 and 14 the solution is a strong alkali the pH of distilled water is 7 Lemon juice, with a pH reading of about 2, is considered to be acid pure water, with a pH of 7 is considered to be neutral substances having a pH value above 9.5 are considered to be alkaline the pH of the skins acid mantle is 4.5-5.5 a characteristic of a weak acid is that it supports the natural pH of the skin a characteristic of a weak alkali is that it softens the stratum corneum of the skin the effect of a strong acid is corrosive and of no use in beauty therapy a characteristic of organic acids is that they contain the element carbon organic acids are found in sebum and plants an organic acid contains the chemical-group COOH an anode is Positively charged electrode a cathode is Negatively charged electrode examples of electrodes which are used in beauty therapy are the needles used for galvanic electrolysis in physics, radiation means the electro-magnetic waves in space the unit of frequency is Hertz in physics, frequency means the number of times per second an electro-magnetic-wave can change direction the unit of frequency is Hertz Hertz is a unit of frequency Invisible rays which can be used in beauty therapy are infra-red and ultra-violet rays infra-red radiation is invisible and can be felt