高一英语视频教学全集,高一视频辅导,由简单学习网一线教师讲课,细致讲解高一各科期中期末必考点,教学效果卓越!高一网课,0元试听,免费学习800讲视频课程,专业辅导,帮助学员突破高分,提高成绩!
Paragraph 1: The periodic table is a chart that reflects the periodic recurrence of chemical and physical properties of the elements when the elements are arranged in order of increasing atomic number (the number of protons in the nucleus). It is a monumental scientific achievement, and its development illustrates the essential interplay between observation, prediction, and testing required for scientific progress. In the 1800's scientists were searching for new elements. By the late 1860's more than 60 chemical elements had been identified, and much was known about their descriptive chemistry. Various proposals were put forth to arrange the elements into groups based on similarities in chemical and physical properties. The next step was to recognize a connection between group properties (physical or chemical similarities) and atomic mass (the measured mass of an individual atom of an element). When the elements known at the time were ordered by increasing atomic mass, it was found that successive elements belonged to different chemical groups and that the order of the groups in this sequence was fixed and repeated itself at regular intervals. Thus when the series of elements was written so as to begin a new horizontal row with each alkali metal, elements of the same groups were automatically assembled in vertical columns in a periodic table of the elements. This table was the forerunner of the modern table. 【TPO16- Development of the Periodic Table】
1. The phrase interplay in the passage is closest in meaning to
○sequence
○interpretation
○requirement
○interaction
