Periodic Table & Atomic Structure
How many protons does an atom with atomic number 12 have?
What is 12 protons
Is NaCl ionic or molecular?
What is Ionic
Name the compound: MgO
What is Magnesium oxide
Is melting ice a chemical or physical change?
What is Physical change
Name one factor that affects reaction rate
What is Temperature, concentration, surface area, catalyst, inhibitor
What does the group number tell you about an element?
What is The number of valence electrons
What type of bond forms between two non-metals?
What is Molecular
Write the formula for sodium nitrate.
What is Na(NO₃)
Name one sign that a chemical change has occurred.
What is Forms a new substance, gas (bubbles), colour change, temperature change, odour, cannot be reversed
What happens to reaction rate when temperature increases?
What is Reaction rate increases
An atom has 14 electrons and is neutral. What is its atomic number, and what element is it?
What is Atomic number 14 and the element is silicon
Why is CO₂ molecular and not ionic?
What is It is made of non-metals only
Name the compound: FeCl₃
What is Iron (III) chloride
Why is burning wood a chemical change?
What is A new substance forms (ash, gas)
Why does a reaction usually happen faster when the temperature is higher?
What is Heat gives particles more energy, so reactions happen more quickly
Why are elements in the same group chemically similar?
What is They have the same number of valence electrons
Why do ionic compounds usually form between metals and non-metals?
What is Metals lose electrons and non-metals gain electrons, allowing charges to balance and form an ionic bond.
Write the formula for ammonium phosphate.
What is (NH₄)₃PO₄
Why is dissolving salt in water a physical change?
What is No new substance forms; salt can be recovered by evaporation
What is the difference between a catalyst and an inhibitor?
What is A catalyst speeds up reactions; an inhibitor slows them down
Magnesium and chlorine are both in Period 3. Explain one reason their chemical behaviour is different.
What is They have a different number of valence electrons, which affects how they react and the ions they form.
Explain why CaCl₂ has a subscript 2 on chlorine.
What is Calcium forms Ca²⁺ and chlorine forms Cl⁻, so two chloride ions are needed to balance the charge.
Name this compound AND explain how you know the charge: Cu₂O
What is Copper (I) oxide because oxygen is –2 total two copper atoms must each be +1 to balance to 0
A student heats copper metal and observes it turn black. Explain why this is a chemical change.
What is Copper reacts with oxygen to form a new substance (copper oxide), shown by the colour change.
Why does crushing a solid often make a reaction happen faster?
What is Crushing increases surface area, allowing the substance to react more easily.