changes
when an object changes its state of matter (solid, liquid and gas)
what does a physical change do?
water
what does hydrogen and oxygen make?
a subscript
what shows how much atoms there are in one element?
the gain of oxygen
what is oxidation
burning magnesium is an oxidation reaction
is burning magnesium oxidation or reduction?
fizzing, bubbling, color changing, temperature changing, scent occurring & matter appearing inside a substance
give an example of a physical change (only 1)
the principle by which a physical quantity remains constant in a system
what does conservation mean? (scientific ver.)
the co-efficient
what multiplies all the atoms in an element?
rusting, rotting, combustion etc.
what is an example of oxidation?
magnesium oxide (MgO)
what is the product of magnesium and oxygen?
a physical change can be restored (reversible) while a chemical change is permanent (irreversible)
total mass of products = total mass of reactants
what is the rule of the conservation of mass?
true
true or false: the atoms are only re-arranged in the product
reduction
is this reduction or oxidation?
CuO+2H->Cu+H2O
balance/scale
what is the piece of apparatus used to measure mass?
false
true or false: physical changes are indicated by a decrease in temperature
59g carbon dioxite
if 25 grams of carbon gets mixed with 34 grams of oxygen, how much grams of carbon dioxide is made?
both reactants and products have the same amount of atoms
what does it mean if an equation is balanced?
magnesium (mg)
what element is being oxidized in the equation?
Mg+CuO->MgO+Cu
false
true or false: magnesium has mass but oxygen does not due to being a gas.
answer has to be about an object changing its volume by getting crushed then getting mixed into another substance
give an example for when a physical change can be converted into a chemical change
reactants:
4 hydrogen, 2 oxygen
products:
4 hydrogen, 2 oxygen
it is balanced
2H2 + O2 -> 2H2O
balanced
is the following equation balanced or unabalanced?
2Fe + 6HC2H3O2 → 2Fe(C2H3O2)3 + 3H2
yes, it can be reversed
can oxidation be reversed?
intense brightness, radiation from UV and heat.
why is it dangerous to look at burning magnesium?