DescriptionIn chemistry an element is a species of atom having the same number of protons in its atomic nuclei. For example, the atomic number of oxygen is 8, so the element oxygen describes all atoms which have 8 protons. In total, 118 elements have been identified.
Answer:
Let the volume of the block of wood be
V
c
m
3
and its density be
d
w
g
c
m
−
3
So the weight of the block
=
V
d
w
g
dyne, where g is the acceleration due to gravity
=
980
c
m
s
−
2
The block floats in liquid of density
0.8
g
c
m
−
3
with
1
4
t
h
of its volume submerged.So the upward buoyant force acting on the block is the weight of displaced liquid
=
1
4
V
×
0.8
×
g
dyne.
Hence by cindition of floatation
V
×
d
w
×
g
=
1
4
×
V
×
0.8
×
g
⇒
d
w
=
0.2
g
c
m
-3
,
Now let the density of oil be
d
o
g
c
m
-3
The block floats in oil with 60% of its volume submerged.So the buoyant force balancing the weight of the block is the weight of displaced oil =
60
%
×
V
×
d
o
×
g
dyne
Now applying the condition of floatation we get
60
%
×
V
×
d
o
×
g
=
V
×
d
w
×
g
⇒
60
100
×
V
×
d
o
×
g
=
V
×
0.2
×
g
⇒
d
o
=
0.2
×
10
6
=
1
3
=
0.33
g
c
m
−
3
Explanation:
Answer: The sample of wine could be described as numbers 1, 3 & 4
Explanation:
It is a mixture because it is the physical combination of two or more substances
It is a homogeneous mixture because any solid, liquid, or gaseous mixture that has the same proportions of its components throughout any given sample is regarded as a homogeneous mixture
It is a solution because it is a special type of homogeneous mixture composed of two or more substances
Answer:
185.92 L
Explanation:
Given data:
1 mole = 6.022× 10²³ molecules
1 mole = 22.4 L
Volume occupy by 5.0× 10²⁴ molecules
Solution:
1 mole = 6.022× 10²³ molecules
5.0× 10²⁴ molecules × 1 mole / 6.022× 10²³ molecules
0.83× 10¹ mol
8.3 moles
1 mole occupy 22.4 L
8.3 mol × 22.4 L / 1 mol
185.92 L
Answer:
a. name of element is copper it's proton is 29 neutron is 34 and electron is 29
b.name of element is sodium it's proton is 11 neutron is 12 and electron is 11
c.name of element is chlorine it's proton is 17 neutron is 18 and electron is 17
d.name of element is iron it's proton is 26 neutron is 30 and electron is 26
