Mitosis makes new cells and replaces the cells that are old, lost or damaged
Answer:
The answer is both molecule and an element
Hydrogen is the chemical element with the symbol H and atomic number 1. ... At standard conditions hydrogen is a gas of diatomic molecules having the formula H2. It is colorless, odorless, non-toxic, and highly combustible.
Explanation:
Explanation:
Spectator ions refers to elements/molecules that do not form part of the reaction. Basically, these elements/molecules are in the same state in the reactant and product side. From the given reaction, Ca and SO4 change their state from aqueous to solid and Na and Cl do not change their state. Therefore, Na and Cl are spectator ions and Ca and SO4 are not spectator ions.
Answer:
The correct option is C.
Explanation:tr
a) Molar mass of HF = 20 g/mol
Atomic mass of hydrogen = 1 g/mol
Atomic mass of fluorine = 19 g/mol
Percentage of an element in a compound:

Percentage of fluorine:

Percentage of hydrogen:

b) Mass of hydrogen in 50 grams of HF sample.
Moles of HF = 
1 mole of HF has 1 mole of hydrogen atom.
Then 2.5 moles of HF will have:
of hydrogen atom.
Mass of 2.5 moles of hydrogen atom:
1 g/mol × 2.5 mol = 2.5 g
2.5 grams of hydrogen would be present in a 50 g sample of this compound.
c) As we solved in part (a) that HF molecules has 5% of hydrogen by mass.
Then mass of hydrogen in 50 grams of HF compound we will have :
5% of 50 grams of HF = 