I need help this is 7th grade science

Which statement correctly explains whether or not this equation is a balanced equation?

Pavel [41]

The equation is balanced because the reactants are same as its products. so answer is B.

6 0

4 years ago

What are good life notes about science

Grace [21]

Answer:

science is pointless and you will never need it so just get thru the class and let it go.

Explanation:

have a good day in need to get rid of the adds so I'm answering as many questions ap

7 0

3 years ago

Perform the following operation and express the answer in scientific notation 8.6500x10^3+6.5500x10^5

Dafna1 [17]

Taking into account the scientific notation, the result of the sum is 6.6365×10⁵.

<h3>Scientific notation</h3>

First, remember that scientific notation is a quick way to represent a number using powers of base ten.

The numbers are written as a product:

a×10ⁿ

where:

a is a real number greater than or equal to 1 and less than 10, to which a decimal point is added after the first digit if it is a non-integer number.
n is an integer, which is called an exponent or an order of magnitude. Represents the number of times the comma is shifted. It is always an integer, positive if it is shifted to the left, negative if it is shifted to the right.

<h3>Sum in scientific notation</h3>

You want to add two numbers in scientific notation. It should be noted that when the numbers to be added do not have the same base 10 exponent, the base 10 power with the highest exponent must be found.

In this case, the highest exponent is 5.

Then all the values are expressed as a function of the base 10 exponent with the highest exponent. In this case: 8.6500×10³= 0.086500×10⁵

Taking the quantities to the same exponent, all you have to do is add what was previously called the number "a". In this case:

0.086500×10⁵ + 6.5500×10⁵= (0.086500+ 6.5500)×10⁵= <u><em>6.6365×10⁵</em></u>

Finally, the result of the sum is 6.6365×10⁵.

Learn more about scientific notation:

brainly.com/question/11403716

brainly.com/question/853571

#SPJ1

8 0

2 years ago

Order the follow processes from (1) the least work done by the system to (5) the most work done by one mole of an ideal gas at 2

quester [9]

Answer : The order of process from (1) the least work done by the system to (5) the most work done by the system will be:

(1) < (5) < (3) < (4) < (2)

Explanation :

<u>The formula used for isothermally irreversible expansion is :</u>

$w=-p_{ext}dV\\\\w=-p_{ext}(V_2-V_1)$

where,

w = work done

$p_{ext}$ = external pressure

$V_1$ = initial volume of gas

$V_2$ = final volume of gas

<u>The expression used for work done in reversible isothermal expansion will be,</u>

$w=-nRT\ln (\frac{V_2}{V_1})$

where,

w = work done = ?

n = number of moles of gas = 1 mole

R = gas constant = 8.314 J/mole K

T = temperature of gas = $25^oC=273+25=298K$

$V_1$ = initial volume of gas

$V_2$ = final volume of gas

First we have to determine the work done for the following process.

(1) An isothermal expansion from 1 L to 10 L at an external pressure of 2.5 atm.

$w=-p_{ext}(V_2-V_1)$

$w=-(2.5atm)\times (10-1)L$

$w=-22.5L.atm=-22.5\times 101.3J=-2279.25J$

(2) A free isothermal expansion from 1 L to 100 L.

$w=-nRT\ln (\frac{V_2}{V_1})$

$w=-1mole\times 8.314J/moleK\times 298K\times \ln (\frac{100L}{1L})$

$w=-11409.6J$

(3) A reversible isothermal expansion from 0.5 L to 4 L.

$w=-nRT\ln (\frac{V_2}{V_1})$

$w=-1mole\times 8.314J/moleK\times 298K\times \ln (\frac{4L}{0.5L})$

$w=-5151.97J$

(4) A reversible isothermal expansion from 0.5 L to 40 L.

$w=-nRT\ln (\frac{V_2}{V_1})$

$w=-1mole\times 8.314J/moleK\times 298K\times \ln (\frac{40L}{0.5L})$

$w=-10856.8J$

(5) An isothermal expansion from 1 L to 100 L at an external pressure of 0.5 atm.

$w=-p_{ext}(V_2-V_1)$

$w=-(0.5atm)\times (100-1)L$

$w=-49.5L.atm=-49.5\times 101.3J=-5014.35J$

Thus, the order of process from (1) the least work done by the system to (5) the most work done by the system will be:

(1) < (5) < (3) < (4) < (2)

8 0

3 years ago

What is a possible reason that ecosystem 2 has fewer species than ecosystem 1?

olganol [36]

it doesn't repopulate as fast because ecosystem 2 could have more trouble reproducing then ecosystem 1.

7 0

4 years ago