Answer:
About 1.254 moles
Explanation:
The first step is to find the molar mass of selenium. If you take a look at a periodic table, you will find that there is a little number underneath that says something around 78.96 g/mol. Dividing 99 grams by this number, you get about 1.254 moles of Se. Hope this helps!
Answer:
1. earth metal 2. halogen 3.The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups. ... Elements in the periodic table are organized according to their properties.
Inventor: Dmitri Mendeleev please name most brainliest
Answer:
A bird's feathers are supposed to keep the bird warm and help them fly. A tree's bark is supposed to protect the inside of the tree.
Explanation:
If a tree has no bark, the inside of it is exposed. If a bird has no feathers, the bird is cold and cant fly.
Answer:
D)both the forward and reverse reactions continue.
Explanation:
Chemical equilibrium can be regarded as state whereby rate of the forward reaction is equal to rate of backward reaction. It should be noted that At equilibrium both the forward and reverse reactions continue.
Answer:
B. A Tin, Sn, atom contains 50 electrons outside the nucleus and 69 neutrons inside the nucleus
Explanation:
Tins number of electron and neutron are of number mostly found yet Ne has its neutron 10 mostly but it's 11 here
i guess
