True or false: Gravity plays an important role in the formation of stars.

How is "food" produced in ecosystems without sunlight?

NeX [460]

Answer:

A Chemosynthesis

Explanation:

5 0

3 years ago

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[please answer fast!] If the hydroxide ion concentration is 2x10^-3 M, what is the pH of the solution? Show your working.

Verizon [17]

Answer:

pH = 11.30

Explanation:

pH is defined as -log [H⁺]

To find [H⁺] from [OH⁻] -Concentration of hydroxide ion-, we must use the equilibrium of water:

H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)

Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]

[H⁺] = 1x10⁻¹⁴ / [OH⁻]

[H⁺] = 1x10⁻¹⁴ / 2x10⁻³M

[H⁺] = 5x10⁻¹²M

pH = -log (5x10⁻¹²M)

6 0

3 years ago

What is arranged to form a material with a crystal structure

mafiozo [28]

Answer:

A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. The scientific study of crystals and crystal formation is known as crystallography.

Explanation:

3 0

3 years ago

For their summer holiday, Jane and her family are visiting places surrounding the Mediterranean Sea. Which type of biome is Jane

elena-14-01-66 [18.8K]

Temperate grassland . .

8 0

4 years ago

A gas has an initial volume of 52.3 L at 273 Kelvin. What is its temperature when the volume reaches 145.7 L?

erastovalidia [21]

Answer:

$\boxed {\boxed {\sf 761 \ K}}$

Explanation:

We are asked to find the new temperature of a gas after a change in volume. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula for this law is:

$\frac {V_1}{T_1}= \frac{V_2}{T_2}$

The volume is initially 52.3 liters at a temperature of 273 Kelvin.

$\frac {52.3 \ L}{273 \ K}= \frac{V_2}{T_2}$

The volume reaches 145.7 liters at an unknown temperature.

$\frac {52.3 \ L}{273 \ K}= \frac{145.7 \ L }{T_2}$

We are solving for the new temperature, so we must isolate the variable T₂. Cross multiply. Multiply the first numerator and second denominator, then the first denominator and second numerator.

$52.3 \ L * T_2 = 273 \ K * 145.7 \ L$

Now the variable is being multiplied by 52.3 liters. The inverse of multiplication is division. Divide both sides by 52.3 L.

$\frac {52.3 \ L * T_2 }{52.3 \ L}=\frac{ 273 \ K * 145.7 \ L}{52.3 \ L}$

$T_2=\frac{ 273 \ K * 145.7 \ L}{52.3 \ L}$

The units of liters cancel.

$T_2=\frac{ 273 \ K * 145.7 }{52.3 }$

$T_2 = 760.5372849 \ K$

The original measurements have at least 3 significant figures, so our answer must have 3. For the number we found, that is the ones place. The 5 in the tenths place tells us to round the 0 up to a 1.

$T_2 \approx 761 \ K$

When the volume reaches 145.7 liters, the temperature is <u>761 Kelvin.</u>

8 0

3 years ago