Answer: Its average atomic mass is 114.9 amu
Explanation:
Mass of isotope 1 = 113 amu
% abundance of isotope 1 = 5% = 
Mass of isotope 2 = 115 amu
% abundance of isotope 2 = 95% = 
Formula used for average atomic mass of an element :

![A=\sum[(113\times 0.05)+(115\times 0.95)]](https://tex.z-dn.net/?f=A%3D%5Csum%5B%28113%5Ctimes%200.05%29%2B%28115%5Ctimes%200.95%29%5D)

Thus its average atomic mass is 114.9 amu
The correct answers are:
1. B. Mg loses two electrons.
When Mg and Br combine, 2 atoms of Br attaches itself to
Mg. The chemical reaction is:
Mg + Br ---> MgBr2
Since Br is more electronegative than Mg, then Mg loses
an electron per Br therefore losing 2 electrons.
2. D. An atom that gains electrons must be attracted to an atom
that loses electrons.
An ionic bond is formed when one molecule is more
electronegative than the other molecule which results in gaining and losing of
electrons. The more electronegative molecule gains electron while the less
electronegative loses electron.
Good grief, this stuff got caught in a black hole somewhere. It is terribly dense.
1 mL = 1 cc under normal conditions.
d = mass / volume
m = 20 kg
v = 5 mL
d = 20kg / 5 mL
d = 4 kg / mL
d = 4 kg / cc
A <<<<answer
For 100m Race ,
displacement = distance covered .
divide the above equation by time t (assuming it takes t time to complete 100m race),
we get,
velocity = speed.
and for 400m race 1 lap is completed this means that racer's initial and final position coincide (or same) hence,
displacement = 0,
distance ≠0=400m.
=> displacement ≠distance.
=> velocity ≠ speed.
Answer:
Solid: calcium and potassium
Liquid: mercury and bromine
Gaseous: oxygen and fluorine
Explanation:
Matter exists in three different states namely: solid, gaseous and liquid. Elements that are found in nature are classified as matter. Since, these elements are grouped as matter, they can either be found as either solids, liquids or gases at normal temperature and pressure.
At normal temperature (20°C or 293K) and pressure (1 atm), the following elements are found to exists in the respective state of matter:
Solid: Calcium (Ca) and potassium (K)
Liquid: Mercury (Hg) and bromine (Br)
Gaseous: Oxygen (O) and fluorine (F)