Answer:
2:A handwarmer gets warm when it is opened and exposed to air.
3:Propane ignites to heat a grill.
4:Cotton is dyed red to make a dress.
Explanation:
The definition of a chemical property is when a property of characteristic of a substance that is <em><u>observed</u></em> during a reaction in which a chemical has been changed
Answer:
2.21 x 10⁻⁷m⁻¹
Explanation:
Given parameters:
Energy of the photon = 9.02 x 10⁻¹⁹J
Unknown:
Wavelength of the photon = ?
Solution;
The wavelength and energy of a photon are related using the expression below;
E = 
h is the Planck's constant = 6.63 x 10⁻⁴m²kg/s²
c is the speed of light
E is the energy
h c = E x wavelength
Wavelength = 
= 
Wavelength = 2.21 x 10⁻⁷m⁻¹
The atomic number? If you mean in an atom, then the number of protons is the atomic number or proton number of an atom
1 mol = 6.022 x 10²³ atoms
In order to find how many atoms, dimly multiply the amount of moles you have by 6.022 x 10²³ or Avogadro's number.
So you have 1.75 mol CHC1₃ x (6.022x10²³) = 1.05385 x 10²⁴ atoms of CHCl₃
But now you have to round because of the rules of significant figures so you get 1.05 x 10²⁴ atoms of CHCl₃
