A
single oxygen has atomic number 8 that means the nuclei of all oxygen atoms
have eight protons. The number of minus-charged electron is two but the number
of electrons is 10. <span>To gain a minus two-charge ion, it
must have two more negative electrons than positive charged protons. With this,
the ion has 10 electrons, which give it a -2 net charge. </span>
Answer : The correct option is, 
Explanation :
To calculate the pressure of gas we are using ideal gas equation as:
where,
P = pressure of gas = ?
V = volume of gas = 0.046 L
n = number of moles of gas = 3.4
R = gas constant = 8.314 L.kPa/mol.K
T = temperature of gas = 298 K
Now put all the given values in the above formula, we get:
Therefore, the pressure of gas is,
Answer: Gas , Solid and Liquid
Explanation:
To complete each sentence , One can easily conclude that the various state of matter are in question here.
To further explain better,
(1) Gas molecule is consider to b moving and also move at a faster rate is respect to others.
(2)Solid molecule usual takes a standing still position unless an external pressure acts on it.
(3) Liquid molecule is capable of starting at same location and then move to another location but not at a faster rate compare to gas molecule.
Molecular equation:
<span>Na2CO3 (aq) + CaCl2 (aq) → CaCO3 (s) + 2 NaCl (aq) </span>
<span>Ionic equation: </span>
<span>2 Na⁺ (aq) + CO3²⁻ (aq) + Ca²⁺ (aq) + 2 Cl⁻ (aq) → CaCO3 (s) + 2 Na⁺ (aq) + 2 Cl⁻ (aq) </span>
<span>Net ionic equation: </span>
<span>CO3²⁻ (aq) + Ca²⁺ (aq) → CaCO3 (s)</span>
