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vampirchik [111]
3 years ago
5

Anyone no this please i need help to pass next grade

Chemistry
1 answer:
Anastaziya [24]3 years ago
6 0

Exothermic is when heat escapes an object. So the answer should be the last one.

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Which equation demonstrates that nuclear fusion forms elements that are heavier than helium
GrogVix [38]

Answer: The correct option is 2.

Explanation: There are two types of nuclear reactions:

1) Nuclear fission: These reactions are defined as the reactions in which a heavier unstable nuclei breaks into two or more smaller stable nuclei.

2) Nuclear fusion: These reactions are the ones where two smaller nuclei fuse together or combine together to form a larger nuclei.

In the question, we need to find the fusion reaction which forms elements heavier than helium.

Option 1: In this fusion reaction occurs but the nuclei is Helium itself.

Option 2: In this also fusion reaction occurs and the nuclei is heavier than Helium which is Neon.

_8^{16}\textrm{O}+_2^4\textrm{He}\rightarrow _{10}^{20}\textrm{Ne}

Option 3 and Option 4: These two reactions are nuclear fission reactions of Uranium-235 because one heavier element is breaking into more than 2 products.

Hence, the correct option is 2.

8 0
3 years ago
Read 2 more answers
It takes 90 N of force to lift a box of books off my smiths table. If you can only leave the box 25% of the way up, how many new
leva [86]

Answer:3.6 I think sorry if wrong

Explanation:

90 divided by 25

4 0
2 years ago
Why is BCl3 a non-polar compound?​
Firdavs [7]

Answer:

BCI3 is a non polar compound because there is no neutral in it

4 0
3 years ago
6. An environmental chemist needs a carbonate buffer of pH 10.00 to study the effects of acid rain on limestone-rich soils. To p
pishuonlain [190]

Answer:

[Na₂CO₃] = 0.094M

Explanation:

Based on the reaction:

HCO₃⁻(aq) + H₂O(l) ↔ CO₃²⁻(aq) + H₃O⁺(aq)

It is possible to find pH using Henderson-Hasselbalch formula:

pH = pka + log₁₀ [A⁻] / [HA]

Where [A⁻] is concentration of conjugate base,  [CO₃²⁻] = [Na₂CO₃] and  [HA] is concentration of weak acid, [NaHCO₃] = 0.20M.

pH is desire pH and pKa (<em>10.00</em>) is -log pka = -log 4.7x10⁻¹¹ = <em>10.33</em>

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Replacing these values:

10.00 = 10.33 + log₁₀ [Na₂CO₃] / [0.20]

<em> [Na₂CO₃] = 0.094M</em>

<em />

5 0
3 years ago
PH3, explain why there is a partial positive on hydrogen and partial negative on phosphorus.
Paraphin [41]

Answer:

Phosphorus is more electronegative than hydrogen

Explanation:

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons towards itself thereby making a molecule to be polar. The Pauling scale is the most commonly used to measure electronegativity. Fluorine (the most electronegative element) is assigned a value of 4.0 on the Pauling's scale, and values range down to caesium and francium which are the least electronegative elements.

Electronegativity increases from left to right across the periodic table (across the period) hence, phosphorus is far more electronegative than hydrogen. Being more electronegative than hydrogen, phosphorus attracts the bonding electron pair of the P-H bond closer to itself than hydrogen. Since the electrons of the bond are closer to phosphorus than hydrogen, the phosphorus atom acquires a partial negative charge while the hydrogen atom acquires a partial positive charge.

3 0
3 years ago
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