Answer:
The correct answer is - 4.
Explanation:
As we known and also given that the total of the superscripts that is mass numbers, A in the reactants and products must be the same.The mass of products A can understand and calculated by this -
The sum of the product mass number of products = mass of reactant
237Np93 →233 Pa91 +AZX is the equation,
Solution:
Mass of reactants = 237
Mass of products are - Pa =233 and A = ?
233 + A = 237
A = 237 - 233
A = 4
So the equation will be:
237Np93 →233 Pa91 +4He2 (atomic number Z = 2 ∵ difference in the atomic number of reactant and products)
The two most abundant elements in Earths core are Iron and Nickel.
Hope this helps!
Answer: 1.99 x 10²² molecules H2
Explanation:First we will solve for the moles of H2 using Ideal gas law PV= nRT then derive for moles ( n ).
At STP, pressure is equal to 1 atm and Temperature is 273 K.
Convert volume in mL to L:
750 mL x 1 L / 1000 mL
= 0.75 mL
n = PV/ RT
= 1 atm ( 0.75 L ) / 0.0821 L.atm/ mole.K ( 273 K)
= 3.3x10-² moles H2
Convert moles of H2 to atoms using Avogadro's Number.
3.3x10-² moles H2/ 6.022x10²³ atoms H2 / 1 mole H2
= 1.99x10²² atoms H2
Answer:
a)decrease
b)increase
c)smaller
d)smaller
Explanation:
Ionization energy decreases down the group due to increase in the atomic radius. The distance between the outermost electron and the nucleus increases hence the nuclear attraction for the outermost electrons become smaller and the ionization energy also become smaller as electrons are now easily removed from the outermost shell.
Hence the group of answer choices provided above.
