题干

大多数天然元素存在几种稳定的同位素。许多同位素有重要的用途,例如126C是作为确定原子量标准的原子;21H、31H是制造氢弹的材料;23592U是制造原子弹的材料和核反应堆的原料。同位素示踪法广泛应用于科学研究、工农业生产和医疗技术方面,例如用188O标记化合物确证了酯化反应的历程,13153I用于甲状腺吸碘机能的实验等。下列说法中正确的是

A:168O2188O2互为同位素

B:分子是保持物质化学性质的唯一微粒

C:同种元素的各种同位素原子的质量不同,但化学性质几乎相同

D:题干中涉及了五种具体的核素

上一题 下一题 0.0难度 选择题 更新时间:2016-04-28 07:25:26

答案(点此获取答案解析)

C

同类题5

阅读理解

Dog parks on Long Island

    For dog lovers, parking dogs sometimes might be a problem. From entertainment facilities to park tips, we've collected everything you need to know before you take your pet for an afternoon of outdoor fun.

    ⒈Amagansett, Napeague State Park

Amagansett, Napeague State Park, Route 27. Dogs are allowed on a leash(狗链)in this undeveloped park, which includes trails, wooded areas and roads. Access to the beach. No water source or public bathrooms.

    ⒉East Meadow, Eisenhower Park

East Meadow, Eisenhower Park, Salisbury Park Drive and Stewart Avenue, East Meadow. In addition to dhaded seating, each run has a water source. Permits are free, but required.

    ⒊Calverton, Isaac Park

Calverton, Isaac Park, on the Grumman Site, within Veteran's Memorial Park. Separated by large and small dogs, this half-acre plot has shade trees, seating and access to the beach. Bring your own water' leashed dog can be walked on some trails; Town of Riverhead residents only.

    ⒋Broolhaven, Robinson Duck Farm Dog Park

Broolhaven, Robinson Duck Farm Dog Park, 2903 Montauk Hwy. This 3-acre park has areas for large and small dogs, but no water source. Large-dog area includes a training course. $18 yearly pass for village residents.

    ⒌Massapequa, Clocks Boulevard Park

Massapequa, Clocks Boulevard Park, off Louden Avenue and Sunrise Highway. At larger than 1 acre, this dog park has lots of room to run and wooded areas for shade. Open dawn to dusk. Water sources are available in both the large- and small-dog areas. It has enough parking and seating. Open to Town of Oyster Bay residents.