Isotope ¹⁸F⁻ contains:
1) p⁺ = 9; number of protons.
Fluorine has a<span>tomic number Z = 9 (total number of protons).
2) e</span>⁻<span> = 10; </span>number of electrons.<span>
In element number of electrons and protons are the same, because element has neutral charge, but because in this example, fluorine is anion with negative charge, it has one electron more.
3) n</span>° = 9; number of neutrons.
<span>Mass number
A = 18 is total number of protons and neutrons in a nucleus, so number of neutrons is A-Z = 18-9=9.</span>
Number 1 is Comets and asteroids
Number 2 is Comets are made of ice and rock
Number 3 is Meteor
Answer:6.022 x 10^23 molecules
Explanation: Since one mole of any chemical compound always contains 6.022 x 10^23 molecules, you can calculate the number of molecules of any substance if you know its mass and its chemical formula.
Mass of block, m = 5.26 lb
1 lb = 453.592 g
5.26 lb = 2385.896 g
V = 14 in3
1 in = 2.5 cm
1 in3 = 15.625 cm3
14 in3 = 218.75 cm3
Density = mass/volume
= 2358.896 / 218.75
= 10.783 g/cm3
Answer: It's the circulatory system
Explanation: