reaction

«reaction» in Mova's school dictionary: What someone says, does or feels because of something… — its meaning for a pupil, its sense in the lessons and examples, with 5 sentences of Mova's corpora that use it.

part of speech

noun (a reaction, reactions)

meaning for a pupil

1) What someone says, does or feels because of something that has happened: her reaction to the news was a big smile. tree →

2) In science, a chemical reaction is when substances change into new substances, like vinegar and bicarbonate of soda fizzing. tree →

3) An allergic reaction is when the body responds badly to something, such as nuts or a bee sting. tree →

4) How quickly you respond: fast reactions. tree →

5) In forces, a reaction is the push back in the opposite direction. tree →

6) A reaction can also be a movement that turns back against a change or an earlier way of doing things. tree →

sense in the lessons

In science, signs of a chemical reaction include fizzing (a gas), a colour change, heat or light, or a new solid forming; burning and rusting are reactions that cannot be undone. In health, an allergic reaction can cause a rash, swelling or trouble breathing; a severe one (anaphylaxis) is an emergency — call for help and an adult may use an adrenaline pen. In sport and games, quick reactions help you catch a ball. In stories, a character's reaction shows how they feel. Phrases: "chemical reaction", "allergic reaction", "a quick reaction", "reaction time", "chain reaction".

examples

• What was your reaction when you saw the surprise? tree →
• Mixing vinegar and baking soda causes a fizzy reaction. tree →
• She had an allergic reaction to the peanuts. tree →
• Rusting is a slow chemical reaction. tree →
• Goalkeepers need fast reactions. tree →
• His reaction was to burst out laughing. tree →
• We measured our reaction times with a falling ruler. tree →
• The fizzing told us a reaction was happening. tree →
• When the Hindu reaction against Buddhism came, the Brahmins adapted these, with the omission of Buddha as the central figure. tree →

note

Countable: a reaction, reactions. Verb: react; adjective: reactive. Melting and dissolving are usually changes, not chemical reactions, because no new substance is made. Any sign of a bad allergic reaction (swelling of lips or tongue, wheezing) needs an adult and emergency help at once.

In the corpora

• A firework is a very fast chemical reaction that makes hot gases, light, heat, noise and smoke.
• Breathing and burning are the same kind of reaction: food or fuel joins with oxygen, giving energy, carbon dioxide and water.
• An allergic reaction to a sting needs a doctor straight away.
• Carbon dioxide is heavier than air, so a balloon filled with it from the reaction does not float.
• Cold slows down bacteria, mould and chemical reactions, so food lasts longer in the fridge.

Trees and pragmatics

Every meaning and example of «reaction» parsed by Mova, each sentence with its dependency tree and frames.