Answer: because they have equal numbers of protons
Explanation: Atoms are electrically neutral because they have equal numbers of protons (positively charged) and electrons (negatively charged). If an atom gains or loses one or more electrons, it becomes an ion
Answer:
(A) because there are the same number of atoms of each element shown on both sides
Explanation:
The Law of conservation of mass says that in a reaction the matter of the products should be equivalent to the matter of the reactants and the mass of the system should remain constant over time.
In a chemical reaction, while atoms bond is breaking of 1 substance than new bonds are formed in another substance and new substances are formed. However, in the overall reaction, they keep the same elements, no new elements can go and come from the outside. For example:
HCl + NaOH -----> NaCl + H2O
In this reaction, on both sides the same number of atoms of each element are present.
Answer:
(a) I_A=1/12ML²
(b) I_B=1/3ML²
Explanation:
We know that the moment of inertia of a rod of mass M and lenght L about its center is 1/12ML².
(a) If the rod is bent exactly at its center, the distance from every point of the rod to the axis doesn't change. Since the moment of inertia depends on the distance of every mass to this axis, the moment of inertia remains the same. In other words, I_A=1/12ML².
(b) The two ends and the point where the two segments meet form an isorrectangle triangle. So the distance between the ends d can be calculated using the Pythagorean Theorem:

Next, the point where the two segments meet, the midpoint of the line connecting the two ends of the rod, and an end of the rod form another rectangle triangle, so we can calculate the distance between the two axis x using Pythagorean Theorem again:

Finally, using the Parallel Axis Theorem, we calculate I_B:

Answer:
r = 6.5*10^-3 m
Explanation:
I'm assuming you meant to ask the diameters of the disk, if so, here's it
Given
Quantity of charge on electron, Q = 1.4*10^9
Electric field strength, e = 1.9*10^5
q = Q * 1.6*10^-19
q = 2.24*10^-10
E = q/ε(0)A, making A the subject of formula, we have
A = q / [E * ε(0)], where
ε(0) = 8.85*10^-12
A = 2.24*10^-10 / (1.9*10^5 * 8.85*10^-12)
A = 2.24*10^-10 / 1.6815*10^-6
A = 1.33*10^-4 m²
Remember A = πr²
1.33*10^-4 = 3.142 * r²
r² = 1.33*10^-4 / 3.142
r² = 4.23*10^-5
r = 6.5*10^-3 m
Answer:
The value is 
Explanation:
From the question we are told that
The the peak wavelength is 
Generally according to the Wien's displacement law
Here T is the approximate surface temperature of this star in K so
=> 
Converting to Fahrenheit ,
![T = [400 - 273.15 ] * \frac{9}{5} + 32](https://tex.z-dn.net/?f=T%20%3D%20%5B400%20-%20273.15%20%5D%20%2A%20%5Cfrac%7B9%7D%7B5%7D%20%2B%2032)
=> 