A compound is a substance composed of 2 or more chemical elements.
The model does not represent a compound because it shows two atoms of the same element combined. To be a compound the model would need to contain atoms of different element, represented by different colored balls. Therefore, the picture does not represent a compound. :)
Answer:- The charge is +2.
Explanations:- Z stands for atomic number. The Z is given as 25 means the atomic number of the element is 25. It has 23 electrons. For a neutral atom the number of electrons is same as the atomic number. Since the number of electrons is less than atomic number, the atom must have lost the electrons.
Number of electrons lost = 25 - 23 = 2
If the element lost electrons then it has positive charge. As, the electrons are lost, the charge is +2.
The answer would be the third one listed, Refraction
Answer:
23.92 g
Explanation:
Molar mass of H2SO4 = (2×1)+32+(16×4)= 2+32+48= 82g/mol
H2SO4 + 2NaOH ---> Na2SO4 + 2H2O
I mole of H2SO4 = 2 moles of NaOH
24.5/82 = 24.5/82 × 2
= 0.598 moles of NaOH will neutralize
Mass= mole× molar mass
Molar mass of NaOH= 23+16+1 = 40g/mol
Mass= 0.598 × 40 = 23.92g of NaOH
