Which pair could be genetic clones? look at the photo

A quantity of energy equal to 8.90 × 1012 joules was emitted from a nuclear reaction. What amount of mass was required to be con

Nataly [62]

E = mc^2
E = 8.90 * 10^12 Joules
c = 3 * 10^8 m/s
m = ????

8.90 * 10^12 = m * (3 * 10^8)^2
8.90 * 10^12 = m * 9 * 10^16
9.889 * 10^-4 kg = m <<<<< answer

5 0

3 years ago

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Which of the following represents six molecules of water? 6HO 2 6H 2O 1 6H 2O H 6O

n200080 [17]

Answer:

6H20 represents six molecules of water

8 0

3 years ago

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8. Consider the element Scandium, atomic # 21.

yawa3891 [41]

Explanation:

Scandium has atomic number of 21. This means that in it's neutral state its going to have 21 electrons.

a) The full electronic configuration is given as;

1s2 2s2 2p6 3s2 3p6 3d1 4s2

The final electron is placed in the d orbital. The shell is 3d

(b) When scandium has a charge if +1, it has lost an electron. The total number of electrons would now be 21-1 = 20

The electronic configuration would be given as;

1s2 2s2 2p6 3s2 3p6 4s2

The electron in the 3d orbital would be removed.

4 0

3 years ago

What are mountins ussaly made from

Katarina [22]

Answer:

rocks and earth

Explanation:

hope this helps

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3 years ago

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Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: 2H2O2(l) → 2H2O(l) + O2(g) ΔH =

Mashcka [7]

Answer: The amount of heat released is -7.203 kJ

Explanation:

The given chemical equation follows:

$2H_2O_2(l)\rightarrow 2H_2O(l )+O_2(g);\Delta H=-196kJ$

To calculate the enthalpy change for 1 mole of the hydrogen peroxide, we use unitary method:

When 2 moles of hydrogen peroxide is reacted, the enthalpy of the reaction is -196 kJ

So, when 1 mole of hydrogen peroxide will react, the enthalpy of the reaction will be $\frac{-196}{2}\times 1=-98kJ$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of hydrogen peroxide = 2.50 g

Molar mass of hydrogen peroxide = 34 g/mol

Putting values in above equation, we get:

$\text{Moles of hydrogen peroxide}=\frac{2.50g}{34g/mol}=0.0735mol$

To calculate the heat of the reaction, we use the equation:

$\Delta H_{rxn}=\frac{q}{n}$

where,

$q$ = amount of heat released

n = number of moles = 0.0735 moles

$\Delta H_{rxn}$ = enthalpy change of the reaction = -98 kJ/mol

Putting values in above equation, we get:

$-98kJ/mol=\frac{q}{0.0735mol}\\\\q=(-98kJ/mol\times 0.0735mol)=-7.203kJ$

Hence, the amount of heat released is -7.203 kJ

8 0

3 years ago