Answer:
5 grams.
Explanation:
Anything that weighs 5 grams, technically, is a pentagram.
Answer:
B. an element
Explanation:
An atom is smallest indivisible particle that takes part in a chemical reaction. Different atoms due to the number of their protons called atomic number gives an element. Every element is a singular atom on it's own. Combination of atoms leads to the formation of molecules and compounds.
When compounds mix together without an actual chemical change, a mixture forms.
Elements are distinct substances that cannot be split up into simpler substances. They are usually made up of only one kind of atom.
Answer:
38 kg/m³
0.038 g/mL
Explanation:
Volume of a cube is the side length cubed.
V = s³
Given s = 0.65 m:
V = (0.65 m)³
V ≈ 0.275 m³
The mass is 10.5 kg. The density is the mass divided by volume:
ρ = (10.5 kg) / (0.275 m³)
ρ ≈ 38 kg/m³
Or:
ρ ≈ 0.038 g/mL
Answer: It will take 3 days for half of a 10 g sample to decay.
Explanation:
Half-life of sample of an isotope X = 3 days
Sample decayed = 
N=
, time = t
![\ln[5 g]=-0.231 day^{-1}\times t\ln[10]](https://tex.z-dn.net/?f=%5Cln%5B5%20g%5D%3D-0.231%20day%5E%7B-1%7D%5Ctimes%20t%5Cln%5B10%5D)
![\ln[\frac{5}{10}]=-0.231\times t](https://tex.z-dn.net/?f=%5Cln%5B%5Cfrac%7B5%7D%7B10%7D%5D%3D-0.231%5Ctimes%20t)
t = 3 days
It will take 3 days for half of a 10 g sample to decay.
