Could a mixture be made up of only one element and no compounds

If 1.27 moles of bromine gas (Br2) react with excess phosphorus (P), how many moles of phosphorus tribromide (PBr3) will be produced?

In a voltaic cell, chemical energy is converted to (1) electrical energy, spontaneously (2) electrical energy, nonspontaneously (3) nuclear energy, spontaneously (4) nuclear energy, nonspontaneously

What is the empirical formula of a compound that contains 50.0% carbon, 6.7% hydrogen, and 43.3% oxygen by mass? A. CH3O B. C3H5O2 C. C2H2O5 D. C3H205 E. C1H3O5

What is the ratio Al 3 + ions to S 2 - ions in a neutral compound

A chemist wishes to prepare a pure sample of silver bromide (agbr). first the chemist combines hydrobromic acid (hbr) and silver hydroxide (agoh) in an aqueous solution. which step should be followed next?

A system consists of two components, each of which must activate if the system is to activate. One component has a reliability of. 99. The other has a reliability of. 95. The components are independent of one another with respect to reliability.

Which of the following energy level changes for an electron is most energetic? 3 → 2 5 → 2 4 → 2

Is baking soda a element compound homogeneous mixture or heterogeneous mixture?

For the reaction: C (CH3) 3I + Cl - → C (CH3) 3Cl + I- What is the activation barrier for the SN2 reaction mechanism, in units of kcal/mol? Provide your answer to the nearest 0.1 kcal/mol.

Which of the following utilizes the measurement of a short - or long-lived radioactive element, with its decay product, to determine the absolute age of an object? A. varves B. radiometric dating C. dendrochronology