What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?

An electron charge e mass m and a positron charge e mass m revolve around their common center of mass under the influence of their attractive coulomb force Find the speed v of each particle in terms of e m k and their separation L

What is waters characteristic shape due to?

A balloon is filled with helium at sea level. What happens to the volume of the balloon in each instance? Explain each answer. a. the balloon floats to a higher altitude. b. the balloon is placed in a bath of liquid nitrogen at - 196C. c.

Which type of graph is best suited to show the breakdown of how this teacher weighs each category?

Consider the reaction: HCl (aq) + NaOH (aq) → NaOH (aq) + H2O (l) How much 0.113 M NaOH solution will completely neutralize 1.25 L of 0.228 M HCl solution?

Henry Moseley organized the periodic table by A. atomic weight. B. atomic number. C. electronegativity. D. overall charge of atoms.

What happens when elements chemically combine? A.) All elements retain their original properties B.) New properties are former C.) Only metals retain their original properties D.) New elements are formed

Which element consists of positive ions immersed in a "sea" of mobile electronsa) sulfur b. nitrogen c. calcium d. chlorine?

1.87e3 m + 24 m + 5.43e-1 km + 1.561e2 km = km

Which 2 continents have the most obvious fit of the coastlines. subject science