Ask question

Ask question

All categories

steposvetlana [31]

2 years ago

7

The half life of potassium 40 is approximately 1.25 billion years. An igneous rock is found to contain about 1/4 of its original

mass of potassium 40. The approximate age of the rock is _____ billion years.

1 answer:

vodomira [7]2 years ago

4 0

Answer:

2.5 billion years

Explanation:

You might be interested in

2.00 L of 0.800 M NaNO3 must be prepared from a solution known to be 2.50 M in concentration.How many mL are required? Plus don'

Morgarella [4.7K]

Answer:

1.36 × 10³ mL of water.

Explanation:

We can utilize the dilution equation. Recall that:

$\displaystyle M_1V_1= M_2V_2$

Where <em>M</em> represents molarity and <em>V</em> represents volume.

Let the initial concentration and unknown volume be <em>M</em>₁ and <em>V</em>₁, respectively. Let the final concentration and required volume be <em>M</em>₂ and <em>V</em>₂, respectively. Solve for <em>V</em>₁:

$\displaystyle \begin{aligned} (2.50\text{ M})V_1 &= (0.800\text{ M})(2.00\text{ L}) \\ \\ V_1 & = 0.640\text{ L} \end{aligned}$

Therefore, we can begin with 0.640 L of the 2.50 M solution and add enough distilled water to dilute the solution to 2.00 L. The required amount of water is thus:
$\displaystyle 2.00\text{ L} - 0.640\text{ L} = 1.36\text{ L}$

Convert this value to mL:
$\displaystyle 1.36\text{ L} \cdot \frac{1000\text{ mL}}{1\text{ L}} = 1.36\times 10^3\text{ mL}$

Therefore, about 1.36 × 10³ mL of water need to be added to the 2.50 M solution.

8 0

2 years ago

1. The speed limit on most city streets is (25 miles). How many meters per minute

irina1246 [14]

Answer:

$Speed = 670.56 \frac{m}{min}$

Explanation:

Given

$Speed = \frac{25 mi}{hr}$

Required

Convert to meters per minutes

$Speed = \frac{25 mi}{hr}$

Start by converting the speed from miles to meters

$1\ mile = 1609.34\ meters.$

So, we have:

$Speed = \frac{25 * 1609.34\ m}{hr}$

$Speed = \frac{40233.5\ m}{hr}$

Next, we convert time from hours to minutes

$1\ hour = 60\ minutes$

So, we have:

$Speed = \frac{40233.5\ m}{60\ min}$

$Speed = 670.56 \frac{m}{min}$

<em>Hence, the equivalent of 25 miles per hour is 670.56 meters per minutes</em>

3 0

2 years ago

Calculate the mass of 6 moles of H2O

RUDIKE [14]

<span>6mole of H2O contains 18×6 g=108 g</span>

8 0

3 years ago

Read 2 more answers

Is wood a homogeneous or heterogeneous mixture?

klio [65]

Wood is a Heterogeneous Mixture.

Hope this helps

5 0

3 years ago

Which reaction creates more massive nuclei?

maxonik [38]

Answer:

C. fusion

hope this helps

6 0

3 years ago