解析 A核心短语/词汇:help sb./ sth. (to) do sth. 帮助某人/某物做某事句子译文:氧气是唯一的助燃气体吗? 本题考查定语从句。___helps fire burn 用来修饰之前的名词gas, 该从句的引导词在定语从句中做主语,不能省略,先行词有only 修饰时不能用which; what 不能引导定语从句,故选项A符合题意。反馈...
What type of element is zirconium? In other words, what is it classified as on the periodic table? What is the name of the Group 1 elements in the periodic table? An element in the lower-left corner of the periodic table: a. is either a metal or metalloid. b. is either a metalloid...
百度试题 结果1 题目What is the chemical symbol for oxygen? A. O B. C C. N D. H 相关知识点: 试题来源: 解析 A。氧的化学符号是 O。碳是 C,氮是 N,氢是 H。本题考查对化学符号的记忆以及细节理解。反馈 收藏
A. It is a product B. It is a reactant C. It is a catalyst D. It has no role 相关知识点: 试题来源: 解析 A。中文解析:氧气在光合作用中是产物,光合作用利用二氧化碳和水产生葡萄糖和氧气,选项 B 反应物是二氧化碳和水,选项 C 催化剂在光合作用中不存在,选项 D 说法错误。反馈...
A.that B./ C.what D.it相关知识点: 试题来源: 解析 A 考查定语从句。Gas为先行词,在定从___ helps fire burn中作主语,且that作主语时不可省略。所以选A。 分析总结。 gas为先行词在定从helpsfireburn中作主语且that作主语时不可省略反馈 收藏 ...
Oxygen is a gaseous chemical element vital to respiration. Although pure oxygen is used medicinally, it can be dangerous when...
Kensal E. van HoldeSpringer Berlin HeidelbergDecker, H. & Van Holde, K., E. 2011, "Oxygen, Its Nature And Chemistry: What Is So Special About This Element?" in Oxygen and the evolution of life, Springer, Berlin; Heidelberg; New York, pp. 1-18....
what is the charge on the ion typically formed by each element?A.oxygen B.iodine C.sodium D.aluminum E.nickel ,2electrons lost F.magnesium 相关知识点: 试题来源: 解析 a) [O 2-] b) [ I -1 ]c) [Na+1] d) [Al 3+] e) [Ni 2+] f) [Mg 2+]Hope my answer helps~ 反馈 ...
What type of element is element 118? In other words, what is it classified as on the periodic table? What is a representative element in basic chemistry terms? Which element has atomic number = 20? Do not spell out the name of the element. Express your answer using only the proper elem...
What type of element is calcium?Calcium:Calcium is represented by Ca on the periodic table. Its atomic number is 20 and it is silvery gray in color. It is also found in limestone and fossilized remains. It was discovered and first isolated by Humphry Davy....