百度试题 结果1 题目10 An isotope of element Y has 19 protons and 20 neutrons in its nucleus. Which is the symbol for the ion of Y? B2039A YB19192039C YD1919 相关知识点: 试题来源: 解析 B 反馈 收藏
更新1: One last question... If the first element of group 1 pares to the last element of group 2... Which is more reactive? And which element of group 2 equals to the reactivity of any element in group 1? For example Ba = Na?? Just for an example..Your question is...
An atom consists of a nucleus, which contains protons and neutrons, surrounded by electrons. The number of protons determines the element of the atom, while the number of neutrons can vary. Electrons exist in energy levels or shells around the nucleus. 开学特惠 开通会员专享超值优惠 助力考试高...
The first electron affinity of an element describes the energy which is released when one mole of gaseous atoms of the element accepts one mole of electrons. It is an important quantity when predicting reactivity of non-metals.Answer and Explanation: ...
Which element has the lowest electronegativity? a) Be b) F c) Si d) Cl e) Mg In each of the following groups, which element is the most electronegative? Which is the least electronegative? a. Cs, Ba, At. b. Ba, Sr, Ra. c. O, Rb, Mg. Which of the fol...
Has a -1 charge 3. Has a mass about the same as that of a proton 4. Is att The nucleus of an atom consists of which particles? Name three subatomic particles found in the atom of an element. If an atom has 17 electrons, 20 neutrons, and 19 ...
Tin is the 49th most abundant element on Earth and has, with 10 stable isotopes, the largest number of stable isotopes in the periodic table, thanks to its magic number of protons. It has two main allotropes: at room temperature, the stable allotrope is β-tin, a silvery-white, ...
The resulting atom: 1) must be very reactive chemically 2) has an atomic number that is one more than that of X 3) has a mass number that is one less than that of X 4) must be radioactive 5) is the same chemical element as X Q13) Radon-222 is a gas produced by alpha decay....
The experiment team collided energetic antiprotons from LEAR with a heavy element, a challenge for them as well as the LEAR operators. Proving that antihydrogen atoms had been formed required several more weeks of data analysis, but the announcement that nine antihydrogen atoms had been produced ...
If carbon has an atomic number of 6, and a mass number of 14, how many neutrons are in the atom?Which of the following facts allows you to determine that atom A and atom B are isotopes of the same element? a) They each have 6 protons. b) They each have 4 ...