Atoms are made of 3 types of subatomic particles ; protons, neutrons and electrons
protons and neutrons are located inside the nucleus and electrons are found in energy shells around the nucleus. Protons are positively charged, electrons are negatively charged and neutrons are neutral. elements in their ground state are neutral with equal amounts of protons and electrons.
Atomic number is the number of protons. atomic number is characteristic for the element.
atomic number of Be is 4 therefore Be has 4 protons
answer is B. 4
When you assume that the gas is behaving ideally, the gas molecules are very far from each other that they do not have any intermolecular forces. If it behaves this way, you can assume the ideal gas equation:
PV = nRT, where
P is the pressure
V is the volume
n is the number of moles
R is a gas constant
T is the absolute temperature
When the process goes under constant pressure (and assuming same number of moles),
P/nR = T/V = constant, therefore,
T₁/V₁=T₂/V₂
If V₂ = V₁(1+0.8) = 1.8V₁, then,
T₂/T₁ = 1.8V₁/V₁
Cancelling V₁,
T₂/300=1.8
T₂ =540 K
If you do not assume ideal gas, you use the compressibility factor, z. The gas equation would now become
PV =znRT
However, we cannot solve this because we don't know the value of z₁ and z₂. There will be more unknowns than given so we won't be able to solve the problem. But definitely, the compressibility factor method is more accurate because it does not assume ideality.
Answer:
rank from lower to higher electronegativity
16)Li
C
N
17)Ne
C
O
18)Si
P
O
19)K
Mg
P
20)He
S
F
Answer:
22Ω
Explanation:
Given parameters:
Potential difference = 3.3V
Current = 0.15A
Unknown:
Resistance = ?
Solution:
According to ohm's law, potential difference, current and resistance are related by the expression below;
V = I R
where V is the voltage
I is the current
R is the resistance
3.3 = 0.15 x R
R = 
= 22Ω
<h3><u>Answer;</u></h3>
EtO-PHE-NH2 + H+ _______ EtO-PHE-NH3+ Cl-
<h3><u>Explanation;</u></h3>
- <em><u>p-phenetidine is p-ethoxy aniline so the amino group acts as a base. The free electron pair on nitrogen will form a coordinate covalent bond with the H+ from the ionized HCl. </u></em>
- HCl is used for the acid-base reaction in p-phenetidine in amide synthesis of acetophenetidin rather than water becuase HCl's polarity contributes to a reaction driven to the right. It protonates the amine group, making it easy to dissolve.
