Practice PPSC questions with answers and explanations.
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Acid and base properties cancel during neutralization.
The products commonly include a salt and water.
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Antacids contain mild bases.
They reduce acidity and relieve symptoms such as heartburn.
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The stomach secretes hydrochloric acid.
It helps activate digestive enzymes and kill many microbes.
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Vinegar contains dilute acetic acid.
This acid gives vinegar its sour taste and preservative effect.
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Complete combustion of carbon forms carbon dioxide.
Limited oxygen may instead produce carbon monoxide.
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Carbon monoxide competes with oxygen for hemoglobin.
This can deprive organs of oxygen without obvious warning.
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Carbon dioxide does not support combustion and is nonconductive.
It can displace oxygen around a fire.
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The proton number is the atomic number.
Changing the proton number creates a different element.
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O is the chemical symbol for oxygen.
Element symbols use one or two letters.
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Iron's symbol Fe comes from the Latin word ferrum.
It is a common structural metal.
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Sodium's symbol Na comes from the Latin natrium.
It is a highly reactive alkali metal.
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Each water molecule has two hydrogen atoms and one oxygen atom.
Its formula is H₂O.
