Answer:
The heat that was used to melt the 15.0 grams of ice at 0°C is 4,950 Joules
Explanation:
The mass of ice in the beaker = 15.0 grams
The initial temperature of the ice = 0°C
The final temperature of the ice = 0°C
The latent heat of fusion of ice = 330 J/g
The heat required to melt a given mass of ice = The mass of the ice to be melted × The latent heat of fusion of ice
Therefore, the heat, Q, required to melt 15.0 g of ice = 15.0 g × 330 J/g = 4,950 J
The heat that was used to melt the 15.0 grams of ice = 4,950 Joules.
Answer:
Gallium-72
Explanation:
The elements are identified by the number of protons of the atom, which is its atomic number.
In this case the number of protons 39 (atomic number 39) permit you to identify the element as gallium.
Now, to identify the isotope you tell the name of the element and add the mass number.
The mass number is the sum of the protons and the neutrons
In this case, the number of neutrons is the original 39 plus the 2 added suddenly, i.e. 39 + 2 = 41, so the mass number is 31 + 41 = 72
Therefore, the isotope is gallium - 72.
Answer : The Lewis-dot structure and resonating structure of 
is shown below.
Explanation :
Resonance structure : Resonance structure is an alternating method or way of drawing a Lewis-dot structure for a compound.
Resonance structure is defined as any of two or more possible structures of the compound. These structures have the identical geometry but have different arrangements of the paired electrons. Thus, we can say that the resonating structure are just the way of representing the same molecule.
First we have to determine the Lewis-dot structure of .
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is,
As we know that sulfur and oxygen has '6' valence electrons.
Therefore, the total number of valence electrons in = 6 + 4(6) + 2 = 32
According to Lewis-dot structure, there are 12 number of bonding electrons and 20 number of non-bonding electrons.
Hence, the Lewis-dot structure and resonating structure of is shown below.
Answer:
a) Se²⁻> S²⁻ > O²
b) Te²⁻ > I- >Cs+
c) Cs+ > Ba²⁺ > Sr²⁺
Explanation:
(a) Se²⁻, S²⁻, O²⁻
In general, ionic radius decreases with increasing positive charge.
As the charge on the ion becomes more positive, there are fewer electrons.
The ion has a smaller radius. In general, ionic radius increases with increasing negative charge.
For ions of the same charge (e.g. in the same group) the size increases as we go down a group in the periodic table
Se²⁻> S²⁻ > O²
(b) Te²⁻, Cs⁺, I⁻
Te²⁻ > I- >Cs+
Te2- hast the biggest size, because of the double negative charge.
Cs+ has the smallest size since it has the most positive charge, compared to Te2- and I-.
(c) Sr²⁺, Ba²⁺, Cs⁺
Cs+ > Ba²⁺ > Sr²⁺
Cs+ has the biggest size, because its more downward (compared to Sr2+) and more to the left (compared) ot Ba2+.
Sr2+ has the smallest size because it's more upwords (compared to Cs+ and Ba2+)
Answer:
Hi! In this case, the reactioncan be correctly balance according to this: 2Al(s) + 3CuSO4(aq) –> Al2(SO4)3(aq) + 3Cu(s).
Explanation:
In this particulary reaction,two semi-reactions happens.
One involving the metallic aluminum that suffers an oxidation reaction:
Al (s) -> Al3 + (aq) + 3e–
and another is a reduction reaction involving copper;
2e– + Cu2 + (aq) -> Cu (s)
