Answer:
Chimia ne poate ajuta să înțelegem, monitorizăm, protejăm și îmbunătățim mediul din jurul nostru. Chimiștii dezvoltă instrumente și tehnici pentru a ne asigura că putem vedea și măsura poluarea aerului și a apei.
Explanation: I speak english i just know Romanian language
Answer:
C. two atoms of oxygen.
Explanation:
Step 1: Data given
Silicon has 14 electrons
Silicon is part of Group IV, all the elements there have 4 valence electrons.
It can form a compound when 4 valence electrons bind with the 4 valence elctrons of silicon
A. four atoms of calcium.
Calcium has 2 valence elctrons. 4 atoms of calcium <u>cannot bind</u> on 1 atom of silicon since there are only 4 valence electrons.
B. one atom of chlorine.
1 atom of chlorine has 7 valence electrons. Chlorine can bind with an atom with 1 valence electron. Since silicon has 4 valence electrons, they will <u>not bind.</u>
Silicon can bind with 4 atoms of chlorine to form SiCl4
C. two atoms of oxygen.
Oxygen has 6 valence electrons, this means oxygen can bind with an element with 2 valence electrons.
Since silicon has 4 valence electrons, it <u>can bind</u> with 2 atoms of oxygen to form SiO2 (silicon dioxide).
D. three atoms of hydrogen.
Hydrogen has 1 valence electron. 1 hydrogen atom can bind with an element that has 7 valence electrons.
Three atoms of hydrogen can bind with an element that has 5 valence electrons.
Silicon <u>will not</u> bind with 3 atoms of hydrogen ( but can bind with 4 atoms of hydrogen)
Stratus clouds reside below the 6,000ft range.
Altocumulus clouds reside in the 6,500-20,000ft range.
Cirrus clouds reside above the 20,000ft range.
Ordered from highest to lowest, the sequence of clouds will be:
Cirrus
Altocumulus
Stratus
Etaphase is a stage during the process of cell division (mitosis or meiosis). Usually, individual chromosomes cannot be observed in the cell nucleus. However, during metaphase of mitosis or meiosis the chromosomes condense and become distinguishable as they align in the center of the dividing cell.
P = 11.133 atm (purple)
T = -236.733 °C(yellow)
n = 0.174 mol(red)
<h3>Further explanation </h3>
Some of the laws regarding gas, can apply to ideal gas (volume expansion does not occur when the gas is heated),:
- Boyle's law at constant T, P = 1 / V
- Charles's law, at constant P, V = T
- Avogadro's law, at constant P and T, V = n
So that the three laws can be combined into a single gas equation, the ideal gas equation
In general, the gas equation can be written
where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08206 L.atm / mol K
T = temperature, Kelvin
To choose the formula used, we refer to the data provided
Because the data provided are temperature, pressure, volume and moles, than we use the formula PV = nRT
T= 10 +273.15 = 373.15 K
V=5.5 L
n=2 mol
V=8.3 L
P=1.8 atm
n=5 mol
T = 12 + 273.15 = 285.15 K
V=3.4 L
P=1.2 atm
