Answer:
Astatine is a halogen with several isotopes that all have short half-lives.
Which of the following combinations of mass number and neutrons are possible as isotopes of astatine? Choose one or more:
i) A = 211, n = 127
ii) A = 210, n = 125
iii) A = 220, n = 134
iv) A = 207, n = 122
v) A = 209, n = 124
Explanation:
The mass number is the sum of the number of protons and the number of neutrons in an atom.
Atomic number of At(astatine ) =85
That means it has --- 85protons.
Its mass number A=210
Hence, the number of neutrons in At are:
Second option:
ii) A=210 , n=125 is the answer.
<h2><u>Answer:</u></h2>
A nonpartisan iota of Nitrogen has a mass of 18. There are 7 protons in the core of this iota. What number of neutrons, complete electrons, and valence electrons are available
Nitrogen 15 has a nuclear mass of 15. The mass number is # protons in addition to # of neutrons, so for N-15 mass is 15 and the protons are dependably 7 so there must be 15-7=8 neutrons. N-15 has 7 electrons since it has 7 protons and p = e.
Anything with a triple bond ends with -yne so that would be C
Answer:
Barometric pressure is 942.3 cm of column of water.
Explanation:
We can measure barometric pressure by measuring the height h of a column of fluid (this column of fluid exerts the same pressure as the column of air of which we are measuring pressure) using the following formula:
Where ρ is the density of the fluid used and g the acceleration of gravity.
Knowing that both the column of mercury (to match units, we know that 698 mmHg are the same as 69.8 cmHg) and the column of water are representing the same pressure, we can match expressions and find h for the column of water:
The only answer that really makes sense here is the first one, properties. I would go with that one.
