If you take your mom's advice, a. the room will be cooled by minimizing heat transfer by reflection.
The Sun is heating your room by its <em>radiation</em>.
The aluminium foil is shiny, so it reflects the Sun’s radiation back outside the window.
<em>Convection</em> is the transfer of heat caused by the air moving around in your room.
<em>Conduction</em> occurs only when a hot object is in contact with a cooler object.
Physical changes occur when objects or substances undergo a change that does not change their chemical composition. This contrasts with the concept of chemical change in which the composition of a substance changes or one or more substances combine or break up to form new substances.
The correct answer is D :)
Answer:
693K
Explanation:
The enthalpy change in the iron is 3690J
We now apply the formula for enthalpy change which is ΔH=mC∅ where ∅ is the temperature change, m the mass of the substance, and C the specific heat capacity for the substance.
ΔH in this case is 3690J.
Therefore 3690J=21.5g×0.449J/g.K×∅
as we are looking for ∅, we make it the subject of the formula.
∅=3690J/(21.5g×0.44J/g)
∅=390
Temperature=30°C +390
=420°+273
=693K
Molecules are made up by chemically bonding two or more atoms of the same element or different elements, they don’t have charge, and the atoms are bonded by covalent bonds. <span>Lattices have a three- dimensional ordered arrangement of basic units (that can be an atom, molecule or an ion). Lattices are crystalline structures with these repeated basic units. When ions joined with ionic bonds, they form ionic crystals. The formula unit tells us that aluminium hydroxide has a crystal structure made from molecules. </span>
