Answer:
1.09 x 10²⁴ atoms Na
Explanation:
In one mole of NaCl, there is also one mole of Na. To convert between moles and atoms, you need to use Avogadro's number. When writing the conversion, the desired unit (atoms) should be placed in the numerator to allow for the cancellation of units (moles). The final answer should have 3 sig figs to match the given number (1.81 mole).
Avogadro's Number:
6.022 x 10²³ atoms = 1 mole
1.81 moles Na 6.022 x 10²³ atoms
--------------------- x -------------------------------- = 1.09 x 10²⁴ atoms Na
1 mole
1. NaCl
2. CaO
3. KOH
4. MgS
5. CuCO3
6. Al2O3
7. Fe2O3
8. Na2CO3
9. AlHO3
10. (NH4)3N
11. Zn3N2
12. MgCO3
All numbers are subscripts.
Answer:
Iron (Fe)
Explanation:
The number of electrons (-) is usually the same as the number of protons (+) in the atom of the element (unless it is an ion).
The element described has 26 electrons, so we can assume that it has 26 protons as well. The number of protons in an atom is the atomic number of element that the atom is.
Element 26 on the PTE is Iron (Fe), which does rust (oxidation) in air and water.
Answer:
B. It is highly flammable.
Explanation:
Chemical properties deal with how the substance will behave when brought into contact with other substances, and usually have to do with it undergoing some kind of reaction. Flammability is a chemical property.
Density, melting point, and color are all considered physical properties.
Explanation:
An acid is a substance that produces excess hydroxonium ions in solution.
An acid based on the pH scale is a substance that has a low pH. Acid lies within a range of 1-7 on the pH scale.
- A pH of 7 is for neutral compounds like water.
- A pH greater that 7 is for basic compounds.
- In order to raise the pH, we are driving at a substance becoming more neutral or basic.
This can be achieved by adding more base to the solution of the substance. When we add more base, hydroxyl ions will neutralize the excess hydroxonium ions and drag the pH towards that of neutrality.
Addition of more base can eventually make the substance basic.
learn more:
Phosphoric acid brainly.com/question/11062486
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