Physical change: a change in which no new substances are formed. the form of the substance is changed but not it's chemical composition (ice melting, bread toasting)
chemical change: any change that results in the formation of new chemical substances. this type of change modifies molecules and atoms by making and breaking the bonds between atoms! (iron rusting, gas burning)
so basically a physical change just changes the appearance of a substance, but a chemical change changes the makeup on a molecular level. i hope this helps you out!
Answer:
lattice parameter = 5.3355x10^-8 cm
atomic radius = 2.3103x10^-8 cm
Explanation:
known data:
p=0.855 g/cm^3
atomic mass = 39.09 g/mol
atoms/cell = 2 atoms
Avogadro number = 6.02x10^23 atom/mol
a) the lattice parameter:
Since potassium has a cubic structure, its volume is equal to:
v = [(atoms/cell)x(atomic mass)/(p)x(Avogadro number)]
substituting values:
v =[(2)x(39.09)/(0.855x6.02x10^23)]=1.5189x10^-22 cm^3
but as the cell volume is
a^3 =v
![a=\sqrt[3]{v}=\sqrt[3]{1.5189x10^{-22} } = 5.3355x10^-8](https://tex.z-dn.net/?f=a%3D%5Csqrt%5B3%5D%7Bv%7D%3D%5Csqrt%5B3%5D%7B1.5189x10%5E%7B-22%7D%20%7D%20%3D%205.3355x10%5E-8)
cm
for a BCC structure, the atomic radius is equal to
Answer:
Substance 4
Explanation:
Density is defined as mass per unit volume. A substance floats in another when its density is less than that of the substance on which it floats.
If an object is immersed in a denser liquid, it will sink
Since the density of water is 1 g/cm^3, any substance whose density is less than that of water will float in it.
If we look at the table, substance 4 has a density of 0.5g/cm^3. Hence, substance 4 is expected to float in water.
Answer:
5.12
Explanation:
5.22 x 10 - 3 = [?] x 10 - 2 (move - 2 to the other side with changed sign)
5.22 x 10 - 3 + 2 = [?] x 10 (divide both sides by 10)
[?] = (5.22 x 10 - 1) / 10
[?] = 5.12
