Biết nguyên tử X nặng gấp 2,5 lần nguyên tử oxi. Tính nguyên tử khối của X và cho biết X thuộc nguyên tố nào? Viết KHHH của nguyên tố đó.

Write two balanced equations 1. dissolving of solid sodium hydroxide in water 2. the reaction of sodium hydroxide solution with hydrochloric acid

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

Let the ed50 of a recreational drug be defined as the amount required for 50% of a test group to feel high or get a buzz. if the ed50 value of ethanol is 470 mg/kg body mass, what dose would a 70 kg party goer need to quickly consume in order to have a 50% chance of getting a buzz? 235 mg 470 mg 32,900 mg 35,000,000 mg