Describe the ways you can know that a chemical reaction has occurred.

Among teenagers, what is the most commonly used substance?

Mass of moist aggregate sample as brought to the laboratory: 5,306 grams Mass of oven dried aggregate: 5,229 grams Mass of aggregates submerged in water: 3,298 grams Mass of SSD (Saturated Surface Dry) Aggregate: 5,229 grams A stockpile sample

Which physical method can be used for obtaining a sample of salt from a small beaker of salt water? boiling freezing filtration sorting

Dissolving 3.05 g of an impure sample of CaCO₃ in an excess of HCl acid produced 0.636 L of CO₂ (measured at 25°C and 792 mmHg). Calculate the percent by mass of CaCO₃ in the sample. State any assumptions.

If 26.35 ml of a standard 0.1650 m naoh solution is required to neutralize 35.00 ml of h2so4, what is the molarity of the acid solution?

How does food in a fridge cool down

How many electrons would be found in the ion whose symbol is given below? N3-

In an atomic model that includes a nucleus, positive charge is a. located in the space outside the nucleus. b. spread evenly throughout an atom. c. concentrated at multiple sites in an atom. d. concentrated in the center of an atom.

In the Table of Atomic Particles, various symbols have two numbers. The top number represents the atomic mass of the particle, what do the bottom numbers represent? Select all that apply.

A chemist is working on a reaction represented by this chemical equation: FeCl2 + 2KOH → Fe (OH) 2 + 2KCl. If the chemist uses 4.15 moles of iron (II) chloride and 3.