Answer:
Atomic radius of sodium = 227 pm
Atomic radius of potassium = 280 pm
Explanation:
Atomic radii trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
Consider the example of sodium and potassium.
Sodium is present above the potassium with in same group i.e, group one.
The atomic number of sodium is 11 and potassium 19.
So potassium will have larger atomic radius as compared to sodium.
Atomic radius of sodium = 227 pm
Atomic radius of potassium = 280 pm
Molar mass :
NaBr = 103 g/mol
Pb(NO3)2 = 331.20 g/mol
<span><span /><span>Balanced chemical equation :
</span></span>2 NaBr + 1 Pb(NO3)2 = 2 NaNO3 + 1 PbBr<span>2
</span><span>
2*103 g NaBr ------------> 1 * 331.20 g Pb(NO3)2
g NaBr -------------------> 311 g Pb(NO3)2
331.20 g = 2*103*311
331.20 g = 64066
mass ( NaBr ) = 64066 / 331.20
mass ( naBr) = 193,43 g of NaBr
hope this helps!.
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Answer:
3. You should walk fast in moving out.
4. You should stay in the evacuation center. Avoid going back to your car, aftershocks may occur.
5. Do not run
The Alkali Metals- (Group 1A)can be found (excluding hydrogen) in the first column of the periodic table. They all have 1 valence electron and tend to form +1 cations when forming Ionic bonds with non metals.
The Alkali Earth Metals: (Group 2A) can be found in the second column/group on the periodic table. These elements form +2 positively charged cations when forming Ionic bonds with non metals. They also all have 2 valence electrons.
The Halogens: are the elements that make up the second to last group on the periodic table. These elements include Chlorine, Fluorine, Bromine, Iodine, and Astatine. These elements have 7 valence electrons. The usually form a -1 charged anion when forming ionic bonds with metals.
The Noble gases: the very last group on the periodic table. All these elements have 8 valance electrons. Due to the octet rule these atoms are already very stable and rarely react with other elements.
