Science Year 10 Term 1 Flashcards
What are the key components of a first-hand investigation?
Collecting valid and reliable data, following safety procedures, and making accurate observations.
How can you improve the reliability of an experiment?
By repeating trials, using consistent methods, and ensuring accurate measurements.
What is the difference between validity and reliability in an experiment?
Validity refers to whether the experiment tests what it is supposed to, while reliability refers to the consistency of the results.
What is accuracy in scientific experiments?
Accuracy is how close a measurement is to the true value.
How do you present scientific data effectively?
Using tables, graphs, and appropriate scientific language and conventions.
What happens to atoms during a chemical reaction?
Atoms are rearranged to form new substances; they are neither created nor destroyed.
What is the Law of Conservation of Mass?
Mass is neither created nor destroyed in a chemical reaction; total mass of reactants = total mass of products.
What are the types of chemical reactions you need to know?
Combustion, acid reactions (with metals and carbonates), corrosion, precipitation, neutralisation, and decomposition.
What is a combustion reaction?
A reaction where a hydrocarbon reacts with oxygen, releasing heat and light energy.
How do you write a word equation for a chemical reaction?
Reactant(s) → Product(s), e.g., Magnesium + Hydrochloric acid → Magnesium chloride + Hydrogen gas.
What is the importance of balancing chemical equations?
To ensure the Law of Conservation of Mass is followed.
What is a neutralisation reaction?
A reaction between an acid and a base that produces a salt and water.
What is an exothermic reaction?
A reaction that releases heat energy (e.g., combustion).
What is an endothermic reaction?
A reaction that absorbs heat energy (e.g., photosynthesis).
How can you identify if a reaction is exothermic or endothermic?
Exothermic reactions release heat (feel hot), while endothermic reactions absorb heat (feel cold).
What factors should be considered when designing an experiment?
Independent variable, dependent variable, control variables, and method.
What is a risk assessment in an experiment?
A process of identifying potential hazards and implementing safety precautions.
Why is it important to graph data in experiments?
To visually identify trends, patterns, and relationships in data.
Why do different elements produce different flame colors in a flame test?
Because electrons absorb and release specific amounts of energy, emitting characteristic colors.
What is the relationship between electron arrangement and the periodic table?
The number of electron shells and valence electrons determines an element’s chemical properties.
What are the reactants and products in a combustion reaction?
Reactants: Fuel (hydrocarbon) + Oxygen → Products: Carbon dioxide + Water + Energy.
What are the reactants and products of an acid-metal reaction?
Acid + Metal → Salt + Hydrogen gas.
What are the reactants and products of an acid-carbonate reaction?
Acid + Carbonate → Salt + Carbon dioxide + Water.
What is corrosion?
A slow chemical reaction where a metal reacts with oxygen and water to form rust (iron oxide).
What is precipitation in chemistry?
A reaction where two soluble substances form an insoluble solid (precipitate).
What is a decomposition reaction?
A reaction where a single compound breaks down into two or more simpler substances.
What is a neutralisation reaction?
A reaction between an acid and a base that produces a salt and water.
What are some signs that a chemical reaction has occurred?
Formation of a precipitate, color change, gas production (bubbles or fizzing), temperature change, light or sound emission.
How can you test for hydrogen gas?
Use the pop test – insert a lit splint into the gas; if it pops, hydrogen is present.
How can you test for carbon dioxide?
Bubble the gas through limewater; if it turns cloudy, carbon dioxide is present.
How can you test for oxygen gas?
Insert a glowing splint into the gas; if it relights, oxygen is present.
Why must chemical equations be balanced?
To satisfy the Law of Conservation of Mass—atoms cannot be created or destroyed.
Balance this equation: H₂ + O₂ → H₂O
2H₂ + O₂ → 2H₂O
Balance this equation: CaCO₃ → CaO + CO₂
Already balanced
Balance this equation: Na + Cl₂ → NaCl
2Na + Cl₂ → 2NaCl
What does the Law of Conservation of Mass state?
The mass of any one element remains the same before and after a chemical reaction.
Why is mass conserved in chemical reactions?
Atoms cannot be created or destroyed; they are only rearranged.
What is the rate of a chemical reaction?
The speed at which a chemical reaction occurs.
How does the number of collisions affect the reaction rate?
More collisions lead to more reactions, increasing the reaction rate.
What is activation energy?
The minimum energy required for a reaction to occur.
What are the three requirements for a chemical reaction to happen?
- Reactants must collide. 2. Molecules must have sufficient energy. 3. Molecules must have the correct orientation.
How does concentration affect reaction rate?
Higher concentration → More particles → More collisions → Faster reaction.
How does surface area affect reaction rate?
Smaller particles → Greater surface area → More collisions → Faster reaction.
How does temperature affect reaction rate?
Higher temperature → More kinetic energy → More collisions → Faster reaction.
How do catalysts affect reaction rate?
Catalysts lower activation energy, leading to more successful collisions.
What is the first step in balancing a chemical equation?
Assign variables to the coefficients of each reactant and product.
Why do we multiply all coefficients by a common factor when balancing equations?
To ensure all coefficients are whole numbers.
What is an exothermic reaction?
A reaction that releases heat and light.
What is an endothermic reaction?
A reaction that absorbs heat from the surroundings.
What is a neutralization reaction?
A reaction between an acid and a base that forms salt and water.
What happens when acids react with metals?
They produce salt and hydrogen gas.
What is the general formula for a decomposition reaction?
AB → A + B
What is a combustion reaction?
A reaction where a substance reacts with oxygen to produce heat and light.
What is a mnemonic to remember the metal reactivity series?
“Please Stop Calling Me A Careless Zebra Instead Try Learning How Copper Saves Gold.”
Which metals are the most reactive?
Potassium, Sodium, and Calcium.
Which metals are the least reactive?
Copper, Silver, and Gold.
What is the solubility rule mnemonic ‘NAG SAG’ used for?
To remember generally soluble compounds: Nitrates, Acetates, Group 1, Sulfates (exceptions: Ag, Hg, Pb, Sr, Ca, Ba), Ammonium, Group 17 (exceptions: Ag, Hg, Pb).
What is an ionic compound?
A compound formed when one atom transfers electrons to another, creating charged ions.
What are two key properties of ionic compounds?
High melting points and they conduct electricity in solution.
What is a covalent compound?
A compound where atoms share electrons to complete their outer shells.
What are two key properties of covalent compounds?
Low melting points and poor electrical conductivity.
What are two properties of acids?
Sour taste and they turn blue litmus paper red.
What are two properties of bases?
Bitter taste and they turn red litmus paper blue.
What is the key difference between a strong acid and a weak acid?
A strong acid completely dissociates in water, while a weak acid only partially dissociates.
