Among the following, which is an oxidation-reduction reaction? question 13 options: na2s + caco3 → cas + na2co3 2hno3 + mg(oh)2 → mg(no3)2 + 2h2o h2 + f2 → 2hf 3ba(oh)2 + 2h3po4 → ba3(po4)2 + 6h2o

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

warm front forms when a moist, warm air mass slides up and over a cold air mass. as the warm air mass rises, it condenses into a broad area of clouds. a warm front brings gentle rain or light snow, followed by warmer, milder weather.

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