上圆下方的铁丝怎么做出来的?
上圆下方的铁丝是通过金属加工和成型达到的。首先,金属加工人员需要设计出铁丝的形状和尺寸,然后使用金属切割机将一段金属棒材料按照设计的尺寸切割成所需长度。接下来,他们将铁丝送入成型...
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学习化学,观察尤为重要.下面对一些实验现象描述正确的是A.红磷在氧气中燃烧产生大量的白烟B.铁丝在氧气中剧烈燃烧,火星四射,放出热量,生成红色粉末C.硫在空气中燃烧发出明亮的蓝紫色火焰,生成一种来自有刺激性气味的气体D.镁条在空气中燃烧,冒出浓烈的黑烟,放出热量,生成黑色粉末
试题**:A试毛损实执换夜史志排断钢题解析:分析:A、根据红磷在氧气中燃烧的360问答现象进行分析判断.B、根错据铁丝在氧气中燃烧的犯调罗站现象进行分析判断.C、既观根据硫在空气...
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下列物质在空气或氧气中燃烧时,现象描述正确的是A.镁条在空气中燃烧,冒出浓烈的黑来自烟,放出热量,生成黑色粉末B.铁丝在氧气中剧烈燃烧,火星四射,放出热量,生成红色粉末C.木炭在氧气中燃烧,发出白光,产生热量,生成能使澄清石灰水变浑浊360问答的气体D.测定空气中氧气含量的实验里,铜丝加热后由黑色变成红色
试题**:C试题解析:分析:A、根据镁条在空气中燃烧的现象进行分析判断.B、根据铁支单火压征情丝在氧气中燃烧的现象进行分析判断.C、根据木炭在氧气中燃烧的现象进行分析判断.D英、...
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下列物质在空副液散观存统座互气或氧气中燃烧时,现象描述正确的是A.镁条在空气中燃烧,冒出深型浓烈的黑烟,放出热量,生成黑成粉末B.铁丝在氧气中剧烈燃烧,火星四射,放出热量,生成红色粉末C.木炭在氧气中燃烧,发出白光,放出热量,产生能使澄清石灰水变浑烛的气体。D.红磷在空气中燃烧,发出黄色火来自焰,放出热量,产生大量烟雾
试题**:C试题解析:试题分析:A、镁条在空气中燃烧发出耀眼的白光,放出热量,生成一种白色固体;B、铁丝在氧气中剧烈燃烧,火星四射,放出热量,生成黑色固体;括写军交个孙意联拿C、...
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琳琳按照物理属性的不同将六种物品分成了甲、乙两组,其中甲组有铁丝、铅笔芯、水银;乙组有玻璃、陶瓷片、干木棒.琳琳这样分类所依据的物理善械常穿表绍台景众牛属性是A.导电性B.密度两菜破析鱼失景需血C.硬度D.磁性
试题****:A试题解析:分析:分析甲组三种物质的共同特点和乙组三种物质的乱写贵共同特点,得出结论.解答360问答:铁丝、铅笔芯、水银都能够导电,是导体;玻璃、陶瓷片、干木棒都不...
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正确的实验操作是实验成功的重要保证,请对一下实验进行分析。实验内容实验装置过程与分析铁丝在纯氧中燃烧如图所示..来自.
(1)待火柴快燃烧完时,再把铁丝伸入集气瓶;(2)止水夹没有**;(3)型神字代备穿木数令草酸钠分解产生一氧化碳充满玻璃管,排尽空气,防止爆炸;黑色粉末变成红色;你铁谈皮础将岩争...
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氧气是我们身边常见的物质,以下关于氧气的叙来自述不正确 的是A.空气成分中氧气约占空气体积的21%B.鱼、虾能在水中生存是由于氧气易溶于水C.细铁丝360问答在氧气中剧烈燃烧,生成黑色固体D.氧气可以供给呼吸,和体内物质反应而释依放能量,维持生命活动
试题**:B试题解析:分析:由空气的成分可以判断A;由氧气的物理性质可知,氧气不易溶于水;由氧气的化学性质可以判断C、D说法是否正确.解答:A、氧气约占沉免空气总体积的21%,故...
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下列在会计上不作为包装物核算的是( )。A.桶B.纸C.玻璃器D.铁丝此题为多项选择题。请帮忙给出正确**和分析,谢谢!
正确**:BCD谁神满买输你晚许曲宗设【**】BCD【考点】包装物的核算范围【解析】会计上有两种包装物不作为包装物核算:(1)各种包装用的材料,包括纸、绳、铁丝等,作为原材料核算...
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如图所示的物体,其内能的增加是通过做功方式实现的是A来自.反复弯折铁丝B.爆炸的车胎C.熔化的冰D.冰箱里的食品
试题**:A试题解析:分析:改变物体内能的方式有两种:做防该盐陆皮清延轴均功和热传递;它们的不同点是:热传递过程是能量的转移过程,而做功过程是能量的转化过程.解答:A、反复弯折铁...
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下面因临齐远加他对某些实验现象的描述,不正确的是A.铁丝在氧气中燃烧时,火星四射,有黑色物质生成B.氢气在空气中燃烧,产生淡蓝色火焰C.紫色石蕊试剂滴入醋酸溶液,溶液变红胞强革著算停散色D.氢氧化钠溶液滴入氯化铜溶液,出现红褐色沉淀
试题答案:D试题解析:分析:A、根据铁丝燃烧的现象分析;B、根据氢气燃烧的现象分析;C、醋酸显酸性,能使紫色的石蕊试液变成红色;来自D、根据氢氧化铜沉淀是蓝色的分析.解答:解;A...
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实验室做铁丝在氧气中燃烧的实验时,不必要的操作是( )
A解析:根据铁丝燃烧时的注意事项分析解答.
下列物质来自在氧气中燃烧,火星四射、产生黑色固体的是(
B解析:D、根据铁丝在氧气中燃烧的现象进行分析判断.解:A、木炭在氧气中燃传战呼货过负德烧,发出白光,生成能使澄清石灰水变浑浊的气体,故选项错误.
下来自列物质在氧气中燃烧,火360问答星四射,有黑色固体生成的是
D试原题解析:根据磷、木炭、铁、甲烷等物质在氧气中燃烧的反应现象分析判断。A、红磷在氧气中燃烧,发出白光,产生大量的白烟,并放出大量的热,错误;B、木炭在氧气中燃设烧,发出白光,...
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