Answer:
A magnet,
Explanation: -you can cause current to flow,
The magnet moves electrons in the wire arround, only moving it about the coil or the other way arround is necaserry.
Answer:
Number of moles = 0.31 mol
Explanation:
Given data:
Mass of H₃PO₄ = 30.0 g
Number of moles = ?
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass of H₃PO₄ = 98 g/mol
Number of moles = 30.0 g / 98 g/mol
Number of moles = 0.31 mol
Answer:
Pure substance: sugar
A chemical change: occurs when methane is burned.
Explanation:
Pure substances have definite <em>constant compositions</em> (reflected in formulas) and have their own <em>chemical properties</em>. On the other hand, mixtures are made of two or more pure substances (<em>variable composition</em>) and their chemical properties depend on each combination. From the list, only sugar is a pure substance (C₁₂H₂₂O₁₁), whereas seawater, air, lemonade, and milk are mixtures.
Chemical changes (chemical reactions) occur when pure substances transform into others, and therefore there are new formulas. Conversely, in physical changes, pure substances <em>preserve their identity</em> (formula) but have changes in their <em>physical properties</em>. Methane being burned is a chemical change since new substances are formed:
CH₄ + O₂ ⇄ CO₂ + H₂O
Water vaporization, paper shredding and dissolution of solids in liquids are examples of physical changes.
It produces no air pollution
