Question

true or false: in a balanced chemical equation, the number of atoms of each element must be the same on both sides of the arrow.
false
true
which of the following is a skeleton equation? *
carbon + oxygen → carbon dioxide
c(s) + o₂(g) → co₂(g)
2c(s) + o₂(g) → 2co(g)
carbon and oxygen react to form carbon dioxide.
which of these shows a single displacement reaction? *
ab + cd → ad + cb
a + b → ab
a + bc → ac + b
ab → a + b

Explanation:

1. A balanced chemical equation follows the law of conservation of mass, which means the number of atoms of each element must be equal on both sides of the equation.
2. A skeleton equation uses chemical formulas to represent the reactants and products without coefficients for balancing. "Carbon + Oxygen → Carbon Dioxide" is a word - equation, "C(s) + O₂(g) → CO₂(g)" is a balanced chemical equation, "2C(s) + O₂(g) → 2CO(g)" is also a balanced chemical equation, and "Carbon and oxygen react to form carbon dioxide" is a word - equation. The skeleton equation is just the basic form with formulas, so "Carbon + Oxygen → Carbon Dioxide" is the closest to a skeleton equation in word - form.
3. In a single - displacement reaction, one element replaces another element in a compound. The general form is A + BC → AC + B.

Answer:

1. True
2. Carbon + Oxygen → Carbon Dioxide
3. A + BC → AC + B