The atomic number is the simply the number of protons in the atom. So in the first row with atomic number 2, the number of protons is 2.
If the atom has no charge, which I think you can assume for all of these, the number of electrons is equal to the number of protons. So the number of electrons is also 2.
The number of neutrons (which are the particles with no charge in the nucleus) is simply the mass number minus the atomic number i.e. 4 - 2 = 2.
The isotopic symbol is the symbol which is found on the periodic table of elements. There are 2 numbers associated which each element on the table. The larger is the mass number and the smaller is the atomic number. The atomic number or number of protons is what identifies the element. Looking at the periodic table ( https://sciencenotes.org/wp-content/uploads/2015/01/PeriodicTableOfTheElementsBW.pdf or https://simple.wikipedia.org/wiki/Periodic_table_(big) ), it can be seen that the element on the first row above with an atomic number of 2 is Helium with a symbol He. The number that is included with the name is simply the mass number which is 4 in this case, which tells us that this type of helium has 2 neutrons.
Another type (or isotope) of helium is Helium-3 which has one neutron.
Try the next row and post back if you have trouble with it
It’s solved by using a pretty standard formula for efficiency.
Answer:
8.8 m and 52.5 m
Explanation:
The vertical component and horizontal component of water velocity leaving the hose are
Neglect air resistance, vertically speaking, gravitational acceleration g = -9.8m/s2 is the only thing that affects water motion. We can find the time t that it takes to reach the blaze 10m above ground level
t = 3.49 or t = 0.58
We have 2 solutions for t, one is 0.58 when it first reach the blaze during the 1st shoot up, the other is 3.49s when it falls down
t is also the times it takes to travel across horizontally. We can use this to compute the horizontal distance between the fire-fighters and the building
Yes a perch is a consumer.
Answer:
12010
Explanation:
Given:
power time
4,370 25
4,420 22
4,150 26
To find: difference in energy used between the dryer that uses the greatest amount of energy and the dryer that uses the least amount
Solution:
Energy = power × time
For clothes dryer x:
energy = 4370 × 25 = 109250
For clothes dryer y:
energy = 4420 × 22 = 97240
For clothes dryer z:
energy = 4150 × 26 = 107900
Dryer x uses the greatest amount of energy and dryer y uses the least amount of energy.
Difference in energy used between the dryer that uses the greatest amount of energy and the dryer that uses the least amount = 109250 - 97240 = 12010
