题目

主族元素原子失去最外层电子形成阳离子，主族元素原子得到电子填充在最外层形成阴离子。下列各原子或离子的电子排布式错误的是( )A. Ca2＋ 1s22s22p63s23p6 B. O2－ 1s22s23p4C. Fe 1s22s22p63s23p63d64s2 D. Fe2＋ 1s22s22p63s23p63d6 答案：【答案】B【解析】A、钙原子失去2个电子变成钙离子，使次外层变成最外层，所以钙离子核外有18个电子，电子排布式为1s22s22p63s23p6，选项A正确；B、氧原子核外有8个电子，氧原子得2个电子变成氧离子，最外层电子数由6个变成8个，所以氧离子核外有10电子，电子排布式为1s22s23p6，选项B错误；C、铁原子People with a positive attitude toward aging can adjust very well when individual circumstances change. Their positive outlook allows them to   50   to the inevitable physical and biochemical changes of the body that are associated with the natural   51   of aging. With a healthy outlook on the golden years, even unpredictable setbacks and disabilities can be managed   52  . Individual genetic makeup (基因构造) explains the great   53   in the aging rate. Some seniors experience more challenges than others of the same age, and some seniors continue to function better than many younger people. But genetics only   54   about 30 percent of aging. Most of the changes we associate with age   55   factors such as diet and exercise habits; lifestyle issues, including over   56   of alcohol and tobacco, and psychological traits. We can make healthy lifestyle choices by staying   57   both physically and mentally and by   58   a healthy diet. Some of the setbacks associated with advancing age such as   59   eyesight, loss of hearing, forgetfulness, weakness can be forestalled with some active intervention（干预）. Growing older does not always mean you see poorly. Many older people have   60   good eyesight well into their eighties and beyond. However, the single greatest contributor to vision loss is a lifetime of   61   to damaging ultraviolet (紫外线) radiation in sunlight. Carotenoids（类胡萝卜素）, a nutrient found in brightly colored vegetables and fruits, are powerful protectors against free-radical damage. Research shows that simply eating leafy greens and other foods rich in these protective nutrients can   62   vision loss. Problems with hearing can create   63   and insecurity in later years. One of the major causes of age-related hearing loss is damage to the hair cells in the inner ear that transmit sounds to the brain. These hair cells and their nerve endings can be damaged by infections, genetic diseases, or treatment with certain drugs. The most common cause,   64  , is loud noise. 50.   A. stick                B. devote               C. adapt                D. lead 51.   A. progress            B. process              C. program            D. project 52.   A. successfully       B. purposefully      C. unwillingly        D. carefully 53.   A. surprise             B. variation           C. increase             D. possibility 54.   A. relies on            B. accounts for       C. results from              D. lies in 55.   A. involve in         B. relate to            C. combine with     D. substitute for 56.   A. reputation         B. enjoyment               C. consumption      D. encouragement 57.   A. active               B. calm                 C. efficient            D. diligent 58.   A. maintaining              B. feeding             C. surviving           D. controlling 59.   A. keen                B. failing               C. sharp                D. remote 60.   A. generally           B. frequently         C. relatively           D. occasionally 61.   A. contribution      B. introduction       C. explanation        D. exposure 62.   A. cure                  B. relieve                     C. reduce               D. suffer 63.   A. communication  B. isolation            C. competition              D. occupation 64.   A. therefore           B. otherwise          C. moreover          D. however