(4) Zirconium
This element is often used in the chemical production field, and as implants due to its high chemical resistance and stability.
Here is the answer for the three of them
<span>N20 = 16 e-
</span><span>SeCl2 =20
</span><span>PBr3 = 26
Remember that t</span><span>o find the valence electrons in an atom you need to identify what group the element is in. An element in group 1A has 1 valence electron. If the element is in group 2A, then it has two valence electrons.</span>
Charles law gives the relationship between temperature and volume of gases. It states that the volume of gas is directly proportional to temperature at constant pressure.
V / T = k
where V - volume and T - temperature in Kelvin and k - constant

where parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
T1 - 20 °C + 273 = 293 K
substituting these values in the equation

T = 586 K
temperature in celsius = 586 K - 273 = 313 °C
new temperature is 313 °C
In descending order from top:
E
F
D
A
C
B
All you really need to do is remember the symbols of each, and you’ve got it.
Answer:
20 atoms
Explanation:
There are 4 in H2O2 because of 2 hydrogens and 2 oxygens.
Then, multiply by 5 because the coefficient is 5, therefore there are 5 H2O2 molecules.
5 x 4 = 20