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2012年1月份,广西龙江河段检测出重金属镉含量超标,使得沿岸及下游居民饮水安全

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题目:

2012年1月份,广西龙江河段检测出重金属镉含量超标,使得沿岸及下游居民饮水安全遭到严重威胁.重金属镉具有毒性,长期过量接触镉会引起慢性中毒,影响人体肾功能.此次龙江污染处置目前主要使用“弱碱性化学沉淀法应急除镉技术”. 该技术的原理是往江水里投放烧碱或生石灰,提高pH值让水呈弱碱性,使镉不溶于水并从水中分离,形成碳酸镉、氢氧化镉细小颗粒.而往江水里投放聚合氯化铝混凝剂,是为了让悬浮在水中的细小颗粒凝聚成大颗粒,沉淀到河底.

(1)上述除镉技术所投放物质中,属于氧化物的是______,属于碱的是______,属于盐的是______.

(2)已知镉元素的原子序数是48,相对原子质量是112,则镉元素的核电荷数是______,原子核内的中子数是______.

答案:

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D.(D) Diplomatic receptions.

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