atoms are made of 3 types of sub atomic particles- protons, neutrons and electrons
from these 3 particles, electrons are responsible for participating in chemical bonds. therefore chemical properties of elements are based on the number of electrons present.
valence electrons are the number of electrons in the outermost energy shell that are involved in chemical bonds.
atoms with same number of valence electrons are grouped in to columns called groups.
therefore elements of the same group have same number of valence electrons, hence similar chemical properties.
from the options given
only Be and Mg belong to the same group they both belong to group 2 with 2 valence electrons
therefore Be and Mg have similar chemical properties
answer is
1) Be and Mg
Answer:4.42 g= 1 mol/55.845 =.079 moles of Fe
Explanation:Given 4.42 grams of Fe. The atomic weight of Fe(iron) found on the periodic table is 55.845. Divide grams by the atomic weight to convert to moles.
Answer:
NH3
Explanation:
Which salt is least soluble at 90 degrees Celsius
Thank you for posting your question here at brainly. Below is the solution:
<span>moles HClO4 = 0.100 L x 0.18 M = 0.018
moles LiOH = 0.030 L x 0.27 = 0.0081
moles H+ in excess = 0.018 - 0.0081 = 0.0099
total volume = 0.130 L
[H+] = 0.0099/ 0.130= 0.0762 M
pH = 1.12</span>
Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of
= 183.511 g/mole
- First we have to calculate the moles of Cu.

The moles of Cu = 4.7209 moles
From the given chemical formula,
we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of
= 4.4209 moles
- Now we have to calculate the mass of
.
Mass of
= Moles of
× Molar mass of
= 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of
= 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.