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.
Answer: 
Explanation:
If percentage are given then we are taking total mass is 100 grams.So, the mass of each element is equal to the percentage given.
Mass of Mg = 10.89 g
Mass of Cl = 31.77 g
Mass of O = 57.34 g
Step 1 : convert given masses into moles.
Moles of Mg=
Moles of Cl = 
Moles of O =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Mg = 
For Cl = 
For O= 
The ratio of Mg :Cl : O= 1 : 2 : 8
Hence the empirical formula is
Red blood cells are formed by the bone marrow in the center cavity of the bones.
Answer:
1.1713 moles
Explanation:
RFM of N2O5=108
Moles of N2O5= mass/RFM= 63.25/108=0.5856 moles
Mole ratio of N2O5:NO2= 2:4
Therefore moles of NO2= 4/2*0.5856= 1.1713 moles
Answer:
In a Lewis symbol, the symbol for the element is used to represent the atom and its core electrons. Dots placed around the atom are used to indicate the valence electrons. ... In 1916, Gilbert Newton Lewis, an American chemist, suggested that molecules were formed when atoms shared pairs of outer electrons.
Explanation:
