Answer:
z+4
Explanation:
An isotope of an element, atomic number Z, has a mass number 2z+4. How many neutrons are there in the nucleus of the element?o
protons + neutrons =mass number
so
z +neutrons = 2z+4
neutrons = 2z+4 - z=z+4 which is the # of neutrons in the nucle
us
Answer:
1, 2, 3
Explanation:
Using a simple chemical reaction as an example;
2H2 + O2 --> 2H2O
1) number of atoms
In the reactant side (left side of the reaction), there are 4 Hydrogen atoms which is equal with the number of atoms in the product (right side of the reaction). In the reactant side, there are 2 oxygen atoms, same thing with the product side. This means it is conserved.
2) Number of electrons
The number of electrons are also balanced. Although there is sharing of electrons, This means it is conserved.
3) In a chemical reaction, the law of conservation of matter is obeyed. Since the number of atoms is conserved, the mass is also conserved.
4) numbers of molecules
Although this is true for some reactions, it is not always the case as seen in the reaction above. This means it is not conserved.
Well an absorbtion line is a dark line in an absorption spectrum
thats all i can give you right now i didnt quite understand the question but hope it helps
Refer to the diagram shown below.
The piston supports the same load W at both temperatures.
The ideal gas law is
where
p = pressure
V = volume
n = moles
T = temperature
R = gas constant
State 1:
T₁ = 20 C = 20+273 = 293 K
d₁ = 25 cm piston diameter
State 2:
T₂ = 150 C = 423 K
d₂ = piston diameter
Because V, n, and R remain the same between the two temperatures, therefore
If the supported load is W kg, then
Similarly,
Because p₁/p₂ = T₁/T₂, therefore
The minimum piston diameter at 150 C is 20.8 cm.
Answer: 20.8 cm diameter