Answer:
(a) SeF₄
(b) OF₂
(c) N₂O
(d) PCl₃
Explanation:
Write the formula for each compound.
(a) selenium tetrafluoride. According to the name, this compound has 1 atom of Se and 4 atoms of F. The resulting formula is SeF₄, in which Se has the oxidation number 4+ and F has the oxidation number 1-.
(b) oxygen difluoride. According to the name, this compound has 1 atom of O and 2 atoms of F. The resulting formula is OF₂, in which the oxidation number of O is 2+ and the oxidation number of F is 1-.
(c) dinitrogen monoxide. According to the name, this compound has 2 atoms of N and 1 atom of O. The resulting formula is N₂O, in which the oxidation number of N is 1+ and the oxidation number of O is 2-.
(d) phosphorus trichloride. According to the name, this compound has 1 atom of P and 3 atoms of Cl. The resulting formula is PCl₃, in which the oxidation number of P is 3+ and the oxidation number of Cl is 1-.
Answer:
5.625 grams
Explanation:
Start your equation with what you have been given. Place the units you need in your answer on the right side of the equal sign.
225mg
----------- X ----------- X ------------- = ? g
lb
Now start to fill in your equation and use a conversions to get rid of the units you don't want. Convert mg into grams first. The child's weight (25 lb) is placed over 1 just to get the equation lined up properly so you can see how the units cancel out.
225 mg 1 g 25 lb 5.625 g
--------------- X --------------- X ------------- = ---------------
lb 1000 mg 1 1
The lb on the top and bottom cancel each other out and you are left with just grams. Even though it is over one, that is the same at just 5.625 grams.
