Pennies used to be made of copper and zinc and had a mass of of 3.1 g. Today pennies are made of copper-platted zinc and have a mass of 2.5 g. A new penny's mass is what percent of an old penny's mass?

What is an open system?

A negatively charged ion is called an anion. a. true b. false

Determine the enthalpy for this reaction: al (oh) 3 (s) + 3hcl (g) →alcl3 (s) + 3h2o (l) express your answer in kilojoules per mole to one decimal place.

The mass of half mole of electrons is about (mass of electron = 9.1 * 10^-28g)

What is a non example of a lipid

You are measuring the mass of various shapes objecys and identifying their shaped ypu then record the qualitative and quanatitave data in a table is qualitataive wnd which is quatitaive

A positively charged wire is attracted to a negatively charged piece of metal. What force causes this?

Two identical atoms from Area B bond together. What type of bond will they most likely form A. Electrostatic B. Metallic C. Ionic D. Covalent

Which would be the best way to represent the concentration of a 1.75 M K2CrO4 solution? 1.75% K2CrO4 [K2CrO4] (K2CrO4) K2CrO4, [M] = 1.75

Consider the reaction C12H22O11 (s) + 12O2 (g) →12CO2 (g) + 11H2O (l) in which 10.0 g of sucrose, C12H22O11, was burned in a bomb calorimeter with a heat capacity of 7.50 kJ/∘C. The temperature increase inside the calorimeter was found to be 22.0 ∘C.