Answer:
A. They have the same atomic numbers.
Explanation:
Elements are defined based on the atomic number, which is the number of protons in the nucleus: this means that atoms of the same element have always the same number of protons in their nuclei (and so, always the same atomic number).
The other choices are wrong because:
B. They have the same average atomic masses. --> this is false for isotopes, which are atoms of the same element having a different number of neutrons. Since the atomic mass is calculated from the sum of the masses of protons and neutrons in the nucleus, two isotopes of the same element have different atomic mass
C. They have the same number of electron shells. --> this can be false when an atom of an element loses/gains an electron, becoming an ion: in that case, the number of electron shells can change, since the number of electrons has changed.
D. They have the same number of electrons in their outermost shells. --> this is also false in case one of the atoms is an ion, since the number of electrons is different.
When developing a question for a scientific inquiry, the question will ideally :
- be measurable
- Will have various variables that could be used for further testing
- not just simply ask why
hope this helps
Answer:
w = 73 N
Explanation:
Since the box is held by the ropes it means that the resulting tension is equal to the weight of the box
T_res = w
Now, the resulting tension is a combination of the tension of each rope.
Since we want to find the vertical component we must multiply by the cosine of 30 degrees the value of T
T_res = T*cos(30) + T*cos(30)
T_res = 2*(42 N)*(0.866)
T_res = 72.746 N
T_res = w = 72.746 N
Hey there! :D
Plug in what you know.
F=ma
F= force m= mass a= acceleration
200 N= m*8 ms
Divide both sides by 8.
m= 25
The mass is 25.
I hope this helps!
~kaikers
Answer:
a) moves down
b) moves down
c) level remains same
Explanation:
Given that the anchor is initially on the floating boat.
a)
In this condition initially the the volume of water 
displaced is to balance its weight.
Now,
We've, the density of steel 
and the density of water 
When the anchor is dropped into water:
The volume of water displaced be 
which will be equal to the volume of anchor since it is immersed into it.
...................(1)
So the level of water falls when the anchor is dropped into water.
b)
Now, when the anchor is thrown on the ground the water has now less weight to balance so the water level falls down.
c)
When the cork on the from the boat is dropped into the water and it still floats then it must displace same amount of water, hence there should be no change in the water level.
