Answer:
The symbol for an atom indicates the element via its usual two letter symbol, the mass number as a left superscript, the atomic number as a left subscript (sometimes omitted), and the charge as a right superscript.
Explanation:
I hope that helps!! sorry if it dont!
The cardboard sleeves reduce the heatness from the coffee cup. So then the cosumer does not get a burn.
Answer:
The cubic centimeter of boron is 2.
Explanation:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Symbol:
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Given data:
mass of boron = 4.68 g
density of boron = 2.34 g/cm³
volume = ? (cm³)
Solution:
d = m/ v
v = m/d
v = 4.68 g/ 2.34 g /cm³
v = 2 cm³
Positive ions are atoms that have lost an electron from its outtermost shell. It is positive because electrons are negative and the loss of something negative makes it a bit more positive.
A negative ion is larger than its original atom because it's gained an electron.
The more electrons an atomic has on its electron cloud, the bigger the atom.
Hopefully I didn't confuse you, good luck. ♡
<u>Answer:</u> The mass of sample A after given time is 99.05 g.
<u>Explanation:</u>
All the radioactive reactions follows first order kinetics.
The equation used to calculate half life for first order kinetics:
We are given:
Putting values in above equation, we get:
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = 84.2 s
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the reactant = 250 g
[A] = amount left after decay process = ?
Putting values in above equation, we get:
![0.011s^{-1}=\frac{2.303}{84.2s}\log\frac{250}{[A]}](https://tex.z-dn.net/?f=0.011s%5E%7B-1%7D%3D%5Cfrac%7B2.303%7D%7B84.2s%7D%5Clog%5Cfrac%7B250%7D%7B%5BA%5D%7D)
![[A]=99.05g](https://tex.z-dn.net/?f=%5BA%5D%3D99.05g)
Hence, the mass of sample A after given time is 99.05 g.
