Chemical Changes

• When metals react with oxygen, they form a metal oxide
• Gaining oxygen is called an oxidation reaction, where metal atoms are oxidised
• Losing oxygen is called a reduction reaction, where metal atoms are reduced
• Metal + Water → Metal hydroxide + Hydrogen
• The reactivity series lists metals in order of their reactivity towards other substances
• When metals react, they lose electrons and form a positive ion
• The reactivity of a metal depends on its ability to lose electrons and form positive ions
• Oxidation is the loss of electrons
• Reduction is the gain of electrons
• A more reactive element will displace a less reactive element from its compound
• Acid + Metal → Salt + Hydrogen
• Hydrochloric acid produces a salt ending in -chloride, while sulfuric acid produces a salt ending in -sulphate
• Bases are chemicals that can neutralize acids, usually metal oxides or metal hydroxides
• Bases soluble in water are called Alkalis
• In aqueous solutions, alkalis produce Hydroxide ions, while acids produce Hydrogen ions
• When reacting an acid with a Base or an Alkali, you get Salt and water
• When reacting an acid with an Alkali, hydrogen ions react with Hydroxide ions to produce Water
• Salts contain a Positive ion from the Base or the Alkali, and a Negative ion from the Acid
• Acid + metal oxide → Salt + Water
• Acid + metal hydroxide → Salt + Water
• Acid + metal carbonate → Salt + Water + Carbon Dioxide
• When acids react with a metal carbonate, they produce a salt, water, and carbon dioxide
• What has been done in this reaction

  A) reduced

  B) oxidised

  
• Label this please 🙏

  A) alkali

  B) hydrogen

  C) hydroxide

  
• Acids are neutralised by alkalis
• acids are neutralised by metal carbonates
• When metals react with other substances, metal atoms form positive ions
• Reactivity of a metal is related to its ability to form positive ions
• label this

  A) violent

  B) very quick

  C) quick

  D) slow

  
• label this

  A) very quick

  B) quick

  C) fairly slow

  D) slow

  E) very slow

  
• label this

  A) water

  B) acid

  
• reduction involves the loss of oxygen