Alkali metals: left column of your periodic table (not hydrogen, but anything below it). They have one valence electron, which they are happy to share in a reaction.
Halogens: second column from the right of your periodic table. They are one electron short of a full shell, so they are reactive in the opposite way that alkalis are--they want electrons.
Atomic number (number of protons) is the big number on the periodic table square. Hydrogen's is 1.
Atomic mass is a little number down below. For example, Hydrogen's is 1.008.
Neutrons are a tricky subject, because different isotopes of the same element can have different numbers of neutrons. You can't generally get this from the atomic mass, because the atomic mass is a weighted average of naturally occurring isotopes. Hydrogen can have 0,1, or 2 neutrons. To answer this, you'd have to choose a particular isotope from the table of isotopes (a completely different chart from the periodic table) which has a certain number of neutrons: n = weight - Z.
Valence electrons are the electrons in the outermost shell. (The column of the table).
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Number of principal shells is the row of the periodic table. </span>
Answer:
r₁/r₂ = 1/2 = 0.5
Explanation:
The resistance of a wire is given by the following formula:
R = ρL/A
where,
R = Resistance of wire
ρ = resistivity of the material of wire
L = Length of wire
A = Cross-sectional area of wire = πr²
r = radius of wire
Therefore,
R = ρL/πr²
<u>FOR WIRE A</u>:
R₁ = ρ₁L₁/πr₁² -------- equation 1
<u>FOR WIRE B</u>:
R₂ = ρ₂L₂/πr₂² -------- equation 2
It is given that resistance of wire A is four times greater than the resistance of wire B.
R₁ = 4 R₂
using values from equation 1 and equation 2:
ρ₁L₁/πr₁² = 4ρ₂L₂/πr₂²
since, the material and length of both wires are same.
ρ₁ = ρ₂ = ρ
L₁ = L₂ = L
Therefore,
ρL/πr₁² = 4ρL/πr₂²
1/r₁² = 4/r₂²
r₁²/r₂² = 1/4
taking square root on both sides:
<u>r₁/r₂ = 1/2 = 0.5</u>
Answer: (a) The magnitude of its temperature change in degrees Celsius is 
.
(b) The magnitude of the temperature change (change in T = 15.1 K) in degrees Fahrenheit is 
.
Explanation:
(a) Expression for change in temperature is as follows.
= 15.1 K
= 
= 
=
Therefore, the magnitude of its temperature change in degrees Celsius is .
(b) Change in temperature from Celsius to Fahrenheit is as follows.
F = 1.8C + 32
C = 
Since, K = C + 273
or, 
= 1.8 (15.1)
= 
or, =
Thus, we can conclude that the magnitude of the temperature change (change in T = 15.1 K) in degrees Fahrenheit is .
Answer:
The given circuit diagram shows parallel circuit.
Explanation:
In this circuit diagram two bulbs are connected in parallel combination because current flows from the battery gets bifurcated at the junction. Thus, two bulbs are connected in parallel combination.
This parallel combinations of bulbs then connected to the battery given in the diagram. So, the combinations of bulbs are connected in parallel combinations with the battery.
Hence, both bulbs and battery are connected in parallel combinations with each other.
The circuit diagram shown in figure is parallel.
