百度试题 题目What is the atomic number of oxygen?A、2B、6C、8D、20Answer:C 科目四考试网________科目四考试题库相关知识点: 试题来源: 解析 http://www.km4ks.com/st/tk/ 反馈 收藏
Science Chemistry Mass number What is the atomic mass of oxygen?Question:What is the atomic mass of oxygen?Oxygen:Oxygen is the eighth element on the periodic table and it is a gas at room temperature. Oxygen is a byproduct of photosynthesis and used by organisms in respiration. Respiration...
The atomic number of an element is defined as the number of protons in the nucleus of its atom. The nucleus houses very heavy neutrons with no electric charge, and comparatively light protons with positive electric charge. The identity of a substance (i.e., the element present in it...
【题目】Theatomicweightofoxygenis___than___ofthehydrogen. A.15timesheavier;that B.15timesheavier:those C.16timesasheavier;that D.16timesasheavy;those 试题答案 在线课程 【答案】A 【解析】 试题分析:考查倍数表达法。句意:氧原子是氢原子重量的16倍。is16timeshavier是倍数表达法,that代指weight,可知...
百度试题 结果1 题目1.4. Which one of the following elements has the smallest atomic number A A Oxygen B Carbon C. Aluminium D Potassium 相关知识点: 试题来源: 解析 A 反馈 收藏
1-2 Matter is made of atoms If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or the...
Deep-seafloor organisms consume oxygen, which can be measured by in situ benthic chamber experiments. Here we report such experiments at the polymetallic nodule-covered abyssal seafloor in the Pacific Ocean in which oxygen increased over two days to more
Dual-atom catalysts, particularly those with heteronuclear active sites, have the potential to outperform the well-established single-atom catalysts for oxygen evolution reaction, but the underlying mechanistic understanding is still lacking. Herein, a l
‘tension’, that is to say, they are like loaded springs just waiting to go off. Other molecules (often oxygen) hold the ‘key’ to unlocking the spring, and when the springs go off, as you can imagine, it is like a room full of mousetraps and ping-pong balls – and all that ...
1. What is the main idea of the passage? A. New York is a city of glass towers。 B. Glass tower are dangerous for migrating birds。 C. New York adopted new safety standards for buildings。 D. Glass towers are a new trend in the United States。 2. What is the number one ...