Answer:
True
Explanation:
When a star has reached the main sequence stage, hydrogen is converted into helium by nuclear fusion, . Also, the gravity and pressure are balanced because the star does not radiate more heat than it generates. A star usually spends most of its lifetime at this stage.
The Zero Age Main Sequence is the period during the main sequence when a star stops contracting, and begin to fuse hydrogen in its core.
Answer:
The answer is A
Explanation:
A large risk of tailgating is the collision avoidance time being much less than the driver reaction time. Driving instructors advocate that drivers always use the "two-second rule" regardless of speed or the type of road. During adverse weather, downhill slopes, or hazardous conditions such as black ice, it is important to maintain an even greater distance.
Because the number of valence electrons of an element determines the properties and in particular the reactivity of that element.
In fact, elements of the first group (i.e. only one valence electron) have high reactivity, because they can easily give away their valence electron to atoms of other elements forming bonds. On the contrary, elements of the 8th group (noble gases) have their outermost shell completely filled with electrons, so they do not have valence electrons, and they have little or no reactivity at all.
I think it was by boat and coming from over seas
Answer:
In odd nuclei, the left out proton or neutron will contribute to the spin of the nucleus.
Explanation:
The meaning of odd nuclei is atomic mass is odd.
A=odd number.
A=Z+n
Here, Z is proton either it will odd or n will odd which is neutron.
Now according to the shell model the left out proton or neutron will contribute to the spin and parity.
For example,
Take the case of isotope of nitrogen-15.
Here Z is 7, and n is 8 will not contribute in spin.
Now, for Z=7.
Here,
and, L=1.
Fort parity,
Put the value of L.
Parity will be -1.
Now, spin will be
.
