Year 10 chemistry revision

Magnesium is a grey solid that has a shiny surface when scratched. If held in a flame with sufficient oxygen in the air, it will burst into a bright white flame and leave behind a white powder (solid). What is the word equation for this reaction?

• magnesium = magnesium oxide + oxygen

• Mg + O → MgO

• magnesium + oxygen → magnesium oxide

• Mg + O + MgO

Magnesium is a grey solid that has a shiny surface when scratched. If held in a flame with sufficient oxygen in the air, it will burst into a bright white flame and leave behind a white powder (solid). What is the balanced symbol equation for this reaction?

• Mg + O₂ → 2MgO

• Mg + O → MgO

• Mg + O₂ → MgO

• 2Mg + O₂ → 2MgO

Calcium is a grey solid. When placed in water, the water bubbles and feels warm. The bubbles of gas are tested with a match and the gas pops. The water left behind is cloudy feels soapy and tests for calcium hydroxide. What is the word equation

• calcium + calcium hydroxide = water + hydrogen

• calcium + hydrogen → calcium hydroxide + hydrogen

• calcium + water = calcium hydroxide + hydrogen

• calcium + water → calcium hydroxide + hydrogen

Calcium is a grey solid. When placed in water, the water bubbles and feels warm. The bubbles of gas are tested with a match and the gas pops. The water left behind is cloudy feels soapy and tests for calcium hydroxide. What is the balanced symbol equation

• Ca + 2H₂O → Ca(OH)₂ + H₂

• Ca + 2H₂O → Ca(OH) + H₂

• Ca + H₂O → CaOH + H₂

• Ca + H₂O → Ca(OH)₂ + H₂

Calcium is a grey solid. When placed in water, the water bubbles and feels warm. The bubbles of gas are tested with a match and the gas pops. The water left behind is cloudy feels soapy and tests for calcium hydroxide. What is the evidence of a chemical change?

• heat and colour change

• new substances that were not there before (a gas and white cloudy water)

• heat

• bubbles

Magnesium is a grey solid that has a shiny surface when scratched. If held in a flame with sufficient oxygen in the air, it will burst into a bright white flame and leave behind a white powder (solid). What is the evidence there was a chemical reaction?

• flame or heat and a new substance that was not there before (white powder)

• gas turned to solid

• heat

• easily reversed

Which ions have the same electron configuration?

• Mg²⁺, Al³⁺, O^2-

• Mg²⁺, Li⁺, O^2-

• Mg²⁺, Be²⁺, O^2-

• Mg²⁺, Na⁺, S^2-

Which ions have the same electron configuration?

• Li⁺, Al³⁺, O^2-

• Mg²⁺, Li⁺, O^2-

• Li⁺, Be²⁺, He

• Mg²⁺, Na⁺, Cl^-

Which ions have the same electron configuration?

• Li⁺, Al³⁺, N^3-

• Mg²⁺, Cl^-, O^2-

• Li⁺, Be²⁺, Na⁺

• Mg²⁺, O^2-, N^3-

Which ions have the same electron configuration?

• Li⁺, K⁺, Na⁺

• Cl^-, K⁺, Ca²⁺

• Li⁺, Be²⁺, Na⁺

• Mg²⁺, Ca²⁺, N^3-