Which pair must represent atoms of the same element?

Write a balanced chemical equation for each of the following. (A) Solid copper reacts with solid sulfur to form solid copper (I) sulfide. Express your answer as a chemical equation. Identify all of the phases in your answer.

Determine the molarity of a solution prepared by dissolving 4.50 mol of nh4cl in sufficient water to make 2.00 l of solution.

In 36 hours the amount of radioactive substance has reduced from 80 mg to 10 mg. What is the half-life of this isotope?

Each equation is incorrect. find the errors, then rewrite and balance each equation. cl2 + nai → nacl2 + i nh3 → n + h2 na + o2 → nao2

The red lionfish (shown below) is a voracious predator of small fish, including young angelfish and parrotfish. In the Caribbean, red lionfish have no natural predators.

Which of the following statments is true for gas particles? they move freely and combine with each other. they dont move at all they move slowly and in a structured pattern they are constantly in motion and changing position.

The A-36 steel pipe has a 6061-T6 aluminum core. It is subjected to a tensile force of 200 kN. Determine the average normal stress in the aluminum and the steel due to this loading.

How many atoms are in 3.3 moles of copper atoms? A. 1.9 x 10 atoms B. 2.0 x 10^23 atoms C. 2.0 x 10^24 atoms D. 2.0 x 10^-23 atoms

What is the Bronsted-Lowry definition of a base?

Which pair must represent atoms of the same element?