天然放射性现象

天然放射性现象 1(天然放射性现象 1896年，贝克勒耳在铀矿石中发现未知的射线，把这些射线称为α射线、β射线、γ射线，这就是天然放射现象的发现.天然放射现象的发现，说明原子核 具有复杂结构, 原子核可以再分. 2、三种射线的本质和特性 种 本 质 电 速 电 贯 穿 性 类 质 量荷度离 (u) (e) (c) 性 α射氦核 4 +2 0.1 最强 最弱，纸 线 能挡住 β射电子 1/18-1 0.99 较强 较强，穿 线 40 几mm铝板 γ射光子 0 0 1 最弱 最强，穿 线 几cm铅版 三种射线在匀强磁场、匀强电场的偏转情况比较: α γ β β γ α O ? ? ? 3、原子核的衰变规律 AA,44XY(1)α衰变的一般方程为?，He?每发生ZZ,22 solution......" action according to law. 14 results of arsenic content in the sample is calculated according to equation (2) is calculated.dsx18.1.2 rubber plug: there was a hole in the middle. 18.1.3 glass measuring arsenic tubes: full length 18cm, heavy down on thin, since the internal diameter of the tube down to 14cm a 6.5mm, since then gradually narrow and thin, end inside diameter is approximately 1~3mm, end 1cm with a hole, diameter 2mm, narrow and thin parts inserted in the rubber plug, reached out to the small holes just below the rubber plug in the lower part. Coarse upper parts with lead acetate cotton, long-5~6cm, upper end to the nozzle at least 3cm, arsenic in tube, using a round flat top tube above ground level, below there is a hook on each side, for fixed glass hat. 18.1.4 glass Cap: below ground level, with a crescent-shaped Groove, has a round hole in the Center, 6.5mm. Glass cover when using in determination of as, the nozzle of the tube, so precisely circular holes between mercuric bromide paper face down, use a rubber or other suitable method of glass tube caps and measuring arsenic. Chapter 19 sample digestion with the 12th. 20 analysis steps draw a quantitative 5th chapter in the samples Digest Hou set capacity of solution (equivalent to 2G food, 4g vegetables, and fruit, 4mL cold, 5G vegetable oil, other samples reference this volume) and the with volume of reagents blank liquid respectively placed measuring arsenic bottle in the, added 5mL Ki solution (150g/L), and 5 drops acid chloride Asia Tin solution and the 5mL hydrochloride (samples as with nitric acid-perchlorate-sulfuric acid or nitric acid-sulfuric acid Digest liquid, is to minus samples in the sulfuric acid ml number; as with gray of method Digest liquid, Minus the number of ml of hydrochloric acid in the sample), and then add just the right amount of 一次α衰变，新元素与原元素相比较，核电荷数减小2，质量数减少4(α衰变的实质是某元素的原子核同时放出由两个质子和两个中子组成的粒子 1142H，2n,He(即氦核)((核内) 102 AA0YX(2)β衰变的一般方程为?，e(每发生一Z，1Z,1 次β衰变，新元素与原元素相比较，核电荷数增加1，质量数不变(β衰变的实质是元素的原子核内的一个中子变成质子时放射出一个电子((核内110nHe,，)， ,011 (3)γ射线是伴随α衰变或β衰变同时产生的、γ射线不改变原子核的电荷数和质量数(其实质是放射性原子核在发生α衰变或β衰变时，产生的某些新核由于具有过多的能量(核处于激发态)而辐射出光子( (4)半衰期 意义:放射性元素的原子核有半数发生衰变需要的时间(用希腊字母τ表示 11t/,i/,m,m()N,N()公式:，(半衰期由放射性元余原余原22 素的原子核内部本身的因素决定，跟原子所处的物理状态(如压强、温度等)或化学状态(如单质或化合物)无关( solution......" action according to law. 14 results of arsenic content in the sample is calculated according to equation (2) is calculated.dsx18.1.2 rubber plug: there was a hole in the middle. 18.1.3 glass measuring arsenic tubes: full length 18cm, heavy down on thin, since the internal diameter of the tube down to 14cm a 6.5mm, since then gradually narrow and thin, end inside diameter is approximately 1~3mm, end 1cm with a hole, diameter 2mm, narrow and thin parts inserted in the rubber plug, reached out to the small holes just below the rubber plug in the lower part. Coarse upper parts with lead acetate cotton, long-5~6cm, upper end to the nozzle at least 3cm, arsenic in tube, using a round flat top tube above ground level, below there is a hook on each side, for fixed glass hat. 18.1.4 glass Cap: below ground level, with a crescent-shaped Groove, has a round hole in the Center, 6.5mm. Glass cover when using in determination of as, the nozzle of the tube, so precisely circular holes between mercuric bromide paper face down, use a rubber or other suitable method of glass tube caps and measuring arsenic. Chapter 19 sample digestion with the 12th. 20 analysis steps draw a quantitative 5th chapter in the samples Digest Hou set capacity of solution (equivalent to 2G food, 4g vegetables, and fruit, 4mL cold, 5G vegetable oil, other samples reference this volume) and the with volume of reagents blank liquid respectively placed measuring arsenic bottle in the, added 5mL Ki solution (150g/L), and 5 drops acid chloride Asia Tin solution and the 5mL hydrochloride (samples as with nitric acid-perchlorate-sulfuric acid or nitric acid-sulfuric acid Digest liquid, is to minus samples in the sulfuric acid ml number; as with gray of method Digest liquid, Minus the number of ml of hydrochloric acid in the sample), and then add just the right amount of 1(单)放射性元素衰变时放出三种射线，按穿透能力由强到弱的排列顺序是 ( B ) A(,射线，,射线，,射线 B(,射线，,射线，,射线， C(,射线，,射线，,射线 D(,射线，,射线，,射线 2(单)如图，放射源放在铅块上的细 孔中，铅块上方有匀强磁场，磁场 方向度垂直于纸面向外。已知放射 源放出的射线有α、β、γ三种。 下列判断正确的是 ( B ) A(甲是α射线，乙是γ射线，丙是β射线 B(甲是β射线，乙是γ射线，丙是α射线 C(甲是γ射线，乙是α射线，丙是β射线 D(甲是α射线，乙是β射线，丙是γ射线 3(单)关于天然放射现象，下列说法正确的是 ( D) A(放射性元素的原子核内的核子有半数发生变化所需的时间就是半衰期 B(放射性物质放出的射线中，α粒子动能很大，因此贯穿物质的本领很强 C(当放射性元素的原子的核外电子具有较高能量 ,时，将发生衰变 D(放射性的原子核发生衰变后产生的新核从高能solution......" action according to law. 14 results of arsenic content in the sample is calculated according to equation (2) is calculated.dsx18.1.2 rubber plug: there was a hole in the middle. 18.1.3 glass measuring arsenic tubes: full length 18cm, heavy down on thin, since the internal diameter of the tube down to 14cm a 6.5mm, since then gradually narrow and thin, end inside diameter is approximately 1~3mm, end 1cm with a hole, diameter 2mm, narrow and thin parts inserted in the rubber plug, reached out to the small holes just below the rubber plug in the lower part. Coarse upper parts with lead acetate cotton, long-5~6cm, upper end to the nozzle at least 3cm, arsenic in tube, using a round flat top tube above ground level, below there is a hook on each side, for fixed glass hat. 18.1.4 glass Cap: below ground level, with a crescent-shaped Groove, has a round hole in the Center, 6.5mm. Glass cover when using in determination of as, the nozzle of the tube, so precisely circular holes between mercuric bromide paper face down, use a rubber or other suitable method of glass tube caps and measuring arsenic. Chapter 19 sample digestion with the 12th. 20 analysis steps draw a quantitative 5th chapter in the samples Digest Hou set capacity of solution (equivalent to 2G food, 4g vegetables, and fruit, 4mL cold, 5G vegetable oil, other samples reference this volume) and the with volume of reagents blank liquid respectively placed measuring arsenic bottle in the, added 5mL Ki solution (150g/L), and 5 drops acid chloride Asia Tin solution and the 5mL hydrochloride (samples as with nitric acid-perchlorate-sulfuric acid or nitric acid-sulfuric acid Digest liquid, is to minus samples in the sulfuric acid ml number; as with gray of method Digest liquid, Minus the number of ml of hydrochloric acid in the sample), and then add just the right amount of 级向低能级跃迁时，辐射出γ射线 234Th4(双)钍核，具有放射性，它放出一个电子衰变 90 234，，Pa成镤核，伴随该过程放出光子，下列说法中 ,91 正确的 ( BD ) A(该电子就是钍原子核外的电子 B(光子是衰变过程中原子核放出的 , C(给钍元素加热，钍元素的半衰期将变短 D(原子核的天然放射现象说明原子核是可分的 5(单)根据有关放射性知识可知下列说法正确的是C A(氡的半衰期为3.8天，若取4个氡原子核，经7.6天后就一定剩下一个原子核了 ,B(衰变所释放的电子是原子核内的质子转化成中子和电子所产生的 ,,,C(射线一般伴随着或射线产生，在这三种射 ,线中，射线的穿透能力最强，电离能力最弱 ,D(发生衰变时，生成核与原来的原子核相比，中子数减少了4 6(单)某放射性元素经过6 次α衰变和8次β衰变， 生成了新核(则新核和原来的原子核相比 ( D ) A(质子数减少了12 B(质子数减少了20 C(中子数减少了14 D(核子数减少了24 solution......" action according to law. 14 results of arsenic content in the sample is calculated according to equation (2) is calculated.dsx18.1.2 rubber plug: there was a hole in the middle. 18.1.3 glass measuring arsenic tubes: full length 18cm, heavy down on thin, since the internal diameter of the tube down to 14cm a 6.5mm, since then gradually narrow and thin, end inside diameter is approximately 1~3mm, end 1cm with a hole, diameter 2mm, narrow and thin parts inserted in the rubber plug, reached out to the small holes just below the rubber plug in the lower part. Coarse upper parts with lead acetate cotton, long-5~6cm, upper end to the nozzle at least 3cm, arsenic in tube, using a round flat top tube above ground level, below there is a hook on each side, for fixed glass hat. 18.1.4 glass Cap: below ground level, with a crescent-shaped Groove, has a round hole in the Center, 6.5mm. Glass cover when using in determination of as, the nozzle of the tube, so precisely circular holes between mercuric bromide paper face down, use a rubber or other suitable method of glass tube caps and measuring arsenic. Chapter 19 sample digestion with the 12th. 20 analysis steps draw a quantitative 5th chapter in the samples Digest Hou set capacity of solution (equivalent to 2G food, 4g vegetables, and fruit, 4mL cold, 5G vegetable oil, other samples reference this volume) and the with volume of reagents blank liquid respectively placed measuring arsenic bottle in the, added 5mL Ki solution (150g/L), and 5 drops acid chloride Asia Tin solution and the 5mL hydrochloride (samples as with nitric acid-perchlorate-sulfuric acid or nitric acid-sulfuric acid Digest liquid, is to minus samples in the sulfuric acid ml number; as with gray of method Digest liquid, Minus the number of ml of hydrochloric acid in the sample), and then add just the right amount of 7()( BC) 双下列说法正确的是 222226RaRn8886A1α1 (衰变为要经过次衰变和次β衰变 238234UUB11 (衰变为要经过次α衰变和次β衰变9192 232208PbThC6α4 82(衰变为要经过次衰变和次β衰变90 238222RnUD4α4 86(衰变为要经过次衰变和次β衰变92 8(单)由原子核的衰变规律可知( C ) A. 放射性元素一次衰变可同时产生α射线和β射线 B. 放射性元素发生β衰变，产生的新核的化学性质不变 C. 放射性元素衰变的快慢跟它所处的物理、化学状态无关 D. 放射性元素发生β衰变时，产生的新核质量数不变，核电荷数减少l solution......" action according to law. 14 results of arsenic content in the sample is calculated according to equation (2) is calculated.dsx18.1.2 rubber plug: there was a hole in the middle. 18.1.3 glass measuring arsenic tubes: full length 18cm, heavy down on thin, since the internal diameter of the tube down to 14cm a 6.5mm, since then gradually narrow and thin, end inside diameter is approximately 1~3mm, end 1cm with a hole, diameter 2mm, narrow and thin parts inserted in the rubber plug, reached out to the small holes just below the rubber plug in the lower part. Coarse upper parts with lead acetate cotton, long-5~6cm, upper end to the nozzle at least 3cm, arsenic in tube, using a round flat top tube above ground level, below there is a hook on each side, for fixed glass hat. 18.1.4 glass Cap: below ground level, with a crescent-shaped Groove, has a round hole in the Center, 6.5mm. Glass cover when using in determination of as, the nozzle of the tube, so precisely circular holes between mercuric bromide paper face down, use a rubber or other suitable method of glass tube caps and measuring arsenic. Chapter 19 sample digestion with the 12th. 20 analysis steps draw a quantitative 5th chapter in the samples Digest Hou set capacity of solution (equivalent to 2G food, 4g vegetables, and fruit, 4mL cold, 5G vegetable oil, other samples reference this volume) and the with volume of reagents blank liquid respectively placed measuring arsenic bottle in the, added 5mL Ki solution (150g/L), and 5 drops acid chloride Asia Tin solution and the 5mL hydrochloride (samples as with nitric acid-perchlorate-sulfuric acid or nitric acid-sulfuric acid Digest liquid, is to minus samples in the sulfuric acid ml number; as with gray of method Digest liquid, Minus the number of ml of hydrochloric acid in the sample), and then add just the right amount of