Answer:
It weighs about 0.819 kg.
Answer:
2 KNO₃ + 10 K → 5 K₂O + N₂ (option 1)
Explanation:
1. 2 KNO₃ + 10 K → 5 K₂O + N₂
We have in reactant side:
2 K, 2N, 6O and 10 K. In conclussion, 12 K, 2N and 6 O
We have in product side.
10 K, 5O and 2 N
This equation is unbalanced
2. 2 SO₂ + O₂ → 2 SO₃
In reactant side we have 2 S and 6 O
In product side we have 2 S and 6 O
3. SF₄ + 3 H₂O → H₂SO₃ + 4 HF
In reactant side we have 1 S, 4F, 6 H and 3 O
In product side we have 1 S, 4F, 6 H and 3 O
Answer:
Explanation:
There are 118 different known <em>elements</em>.
Each element is identified by the number of protons and it is called the atomic number. For instance, the atomic number of hydrogen is 1, every hydrogen atom has one proton; the atomic number of oxygen is 8, every oxygen atom has 8 protons; the atomic number of carbon is 6, every carbon atom has 6 protons.
There are not two different elements with the same atomic number (number of protons).
The 118 known elements are listed in the periodict table in groups (columns) and periods (rows) in increasing order of atomic number (number of protons).
So, by counting the number of protons of an atom, chemists can tell the element to which the atom belong.
Answer: 72 grams of 
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number 
of particles.
To calculate the number of moles, we use the equation:
Putting in the values we get:
According to stoichiometry:
1 mole of 
requires 5 moles of oxygen
0.45 moles of require= 
moles of oxygen
Mass of 
72 grams of are needed to completely burn 19.7 g
