Chemistry

What is an *atom*? - Ans .smallest part of an element ▪ What is an *element*? - Ans .a substance that contains only one type of atom ▪ What are *chemical symbols*? - Ans .- the letter or pair of letters that represents an element. o first letter is always capitalized ▪ What are *compounds*? - Ans .substances in which atoms of two or more elements, which are chemically combined ▪ What is a *chemical formula*? - Ans .a combination of symbols that shows the ratio of elements in a...

1. What is a mixture? - Ans .Two or more elements not chemically bonded 2. What is the difference between a compound and a mixture? - Ans .Compounds have a fixed composition whereas mixtures do not. Mixtures are not chemically bonded but compounds are. 3. Describe the process of filtration - Ans .Pour the mixture onto the filter paper, the liquid simply passes through the filter paper into the flask. The insoluble solid cannot pass through and so it stays on the paper 4. Describe the pr...

What is an atom? - Ans .Smallest part of an element that can exist ▪ What is an element? - Ans .A substance made up of one type of atom ▪ How are elements represented? - Ans .Using symbols, in the periodic table ▪ Approximately how many elements are there? - Ans .100 ▪ What is a compound? - Ans .A substance made up of two or more elements chemically combined in fixed proportions ▪ How are the elements in a compound separated? - Ans .By chemical reaction ▪ How are chemical rea...

1. What are *atoms*? - Ans .The smallest part of an element that can exist 2. What are *compounds*? - Ans .- They are formed from elements by chemical reactions - Contain 2 or more elements chemically combined in fixed proportions - Can only be separated into elements by chemical reactions 3. What do *chemical reactions* involve? - Ans .The formation of one or more new substances, and often involve detectable energy change 4. What is a *mixture*? - Ans .- Consists of two or more elements/...

What is the radius of an atom? - Ans .0.1 nanometers Where is the nucleus located? - Ans .center of the atom What does the nucleus contain? - Ans .protons and neutrons What charge does a proton have? - Ans .positive What charge does an electron have? - Ans .negative What is the mass of an electron? - Ans .0 what charge does an atom have? - Ans .no charge What does the atomic number tell you? - Ans .number of protons What does the mass number tell you? - Ans .Number of protons and neutron...

▪ How acidic or alkali something is. - Ans .What does the pH scale tell you? ▪ one to six - Ans .What's the pH range for acids? ▪ 7 - Ans .What's the pH of a neutral solution? ▪ Eight to Fourteen - Ans .What's the pH range of an alkali solution? ▪ H+ - Ans .Which ion in an aqueous solution causes acidity? ▪ OH- - Ans .Which ion in an aqueous solution causes alkalinity? ▪ Base + Acid à Salt + Water - Ans .What does BASW stand for? ▪ Metal + Acid à Salt + Hydrogen - Ans...

▪ Potassium manganate (VII) and water (purple colour spreads), ammonia and hydrogen chloride (white ring forms closer to hydrogen chloride), bromine gas and air (brown bromine gas diffuses) - Ans .3 experiments to show diffusion ▪ 4OH- = O2 + 2H2O + 4E- - Ans .Half equation for hydroxide ions ▪ Moves slowly (on the surface), fizzes, eventually disappears - Ans .Lithium with water - observations ▪ Moves quickly (on the surface), fizzes rapidly, may ignite - Ans .Sodium with water ...

1. What is the charge of a proton? - Ans .+1 2. What is the charge of a neutron? - Ans .0 3. What is the charge of an electron? - Ans .-1 4. What is the relative mass of a proton? - Ans .1 5. What is the relative mass of a neutron? - Ans .1 6. What is the relative mass of an electron? - Ans .Very small 7. How many types of atoms do elements contain? - Ans .Only one type 8. What are compounds? - Ans .Substances containing two or more different elements that are chemically bonded together...

Atom definition The smallest component of an element Compound Two or more elements, chemically joined in fixed proportions. They can only be separated by chemical means. Mixture Two or more elements/compounds which are not chemically combined. Ways to separate mixtures - Filtration - Evaporation - Crystallisation - Simple distillation - Fractional distillation - Paper chromatography The plum and pudding model Before electrons were discovered, people thought that atoms were indivi...

▪ What are all substances made of - Ans .atoms. ▪ What is an atom? - Ans .Smallest part of an element that can exist. ▪ What is an element? - Ans .A substance that only contains one type of atom. ▪ How many elements are there? - Ans .about 100. ▪ Where are elements displayed? - Ans .In the periodic table. ▪ How are the atoms of each element represented? - Ans .different chemical symbols. ▪ What are most substances? - Ans .Compounds. ▪ What is a compound? - Ans .2 or more e...