Hydrogen (H) was first, followed by helium (He).
Answer:
kinetic
Explanation:
kinetic energy is the energy possessed by a body due to its motion.
Answer:
element having 2+ valence electrons can transfer its more than one electron that is 2 electron completely.
Explanation:
- Group IIA have 2+ valency and two electrons in its valance shell.
- Its Electropositivity is high and have the tendency to donate it two electrons.
- Element of IIA form ionic with most electronegative element.
Examples:
Cu²⁺, Mg²⁺, Sr²⁺ are examples having 2+ valance electron
one of the following is examples of element that have 2+ valence electrons
MgCl₂
Atomic number of Magnesium (Mg) is 12
Electronic Configuration of Mg:
1s², 2s², 2p⁶, 3s²
or
K =2
L = 8
M = 2
So, it have to give its 2 electrons to form a stable compound.
Similarly
Chlorine atomic number is 17
Electronic Configuration of Chlorine:
1s², 2s², 2p⁶, 3s², 3p⁵
or
K =2
L = 8
M = 7
So, it have to gain one electrons to form a stable compound and complete its octet.
So,
Two chlorine atom as a molecule gain 2 electrons from Mg²⁺ atom
So one Mg²⁺ and 2 Cl⁻ atoms form an ionic bond
where in this ionic bond Mg²⁺ transfer its 2 valence electron completely and chlorine molecule accept 2 electrons.
Cl-----Mg------Cl
So the Answer is
element having 2+ valence electrons can transfer its more than one electron that is 2 electron completely.
Answer:
d. why matter exists
Explanation:
The kind of questions that chemistry CANNOT answer is "why matter exists".
In Chemistry, question of how the properties, composition and structure of substances are is answered. Also, the transformations that these substances undergo, and the energy that they release or absorbe during the transformation processes are revealed in chemistry.
Chemistry can answer the question of what forms of matter exists but cannot answer why matter actually exists.
Answer:
81.04°C
Explanation:
Heat loss by water = Heat gained by Aluminum
Heat loss by water;
H = MCΔT
ΔT = 100 - T2
M = 580g
c = 4.2
H = 580 * 4.2 (100 - T2)
H = 243600 - 2436T2
Heat ganed by Aluminium
H = MCΔT
ΔT = T2 - 24
M = 900g
c = 0.9
H = 900 * 0.9 (T2 - 24)
H = 810 T2 - 19440
243600 - 2436T2 = 810 T2 - 19440
243600 + 19440 = 810 T2 + 2436T2
263040 = 3246 T2
T2 = 81.04°C
Assumption;
Assume that energy diffuses throughout the pan and water so that all parts reach the same final temperature.
