For about how long do scientists think wind and solar power can provide us with energy?

A sample of basalt has smaller crystals than a sample of granite. What is the most likely reason for this?

posledela

The most likely reason is that basalt is an extrusive rock, while granite is an intrusive rock. What this means is that basalt forms at the surface of the earth, where temperatures are cooler. Because of the cooler external temperature, basalt cools relatively quickly, and there isn't as much time for mineral crystals within the rock to align to form larger crystals while the rock is cooling. Granite, on the other hand, forms below the surface of the earth, where temperatures are significantly higher. Therefore, it doesn't cool as quickly, and the minerals within granite have more time to form larger crystals and the rock cools.

4 0

3 years ago

What elements are in NaC2HO4 and how many atoms are in each element

JulijaS [17]

Answer:

Each molecule contains one atom of A and one atom of B. The reaction does not use all of the atoms to form compounds.

A + B ⟶ Product

Particles: 6 8 6

If six A atoms form six product molecules, each molecule can contain only one A atom.

The formula of the product is ABₙ.

If n = 1, we need six atoms of B.

If n = 2, we need 12 atoms of B. However, we have only eight atoms of B, so the formula of the product must be AB.

Thus, 6A + 6B ⟶ 6AB, with two B atoms left over.

Explanation:

Credit goes to @znk

Hope it helps you :))

7 0

3 years ago

If we start with 1.000 g of strontium-90, 0.805 g will remain after 9.00 yr. This means that the of strontium-90 is ________ yr.

lesantik [10]

The question is incomplete, here is the complete question.

If we start with 1.000 g of strontium-90, 0.805 g will remain after 9.00 yr. This means that the half-life of strontium-90 is ________ yr.

a. 28.8 b. 30.9 c. 35.4 d. 32.2

Answer : The half-life of strontium-90 is 28.8 years.

Explanation :

This is a type of radioactive decay and all radioactive decays follow first order kinetics.

First we have to calculate the rate constant.

Expression for rate law for first order kinetics is given by :

$k=\frac{2.303}{t}\log\frac{a}{a-x}$

where,

k = rate constant

t = time taken for decay process = 9.00 year

a = initial amount or moles of the reactant = 1.000 g

a - x = amount or moles left after decay process = 0.805 g

Putting values in above equation, we get:

$k=\frac{2.303}{9.00}\log\frac{1.00}{0.805}$

$k=0.0241\text{ year}^{-1}$

To calculate the half-life, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$0.0241\text{ year}^{-1}=\frac{0.693}{t_{1/2}}$

$t_{1/2}=28.8\text{ years}$

Therefore, the half-life of strontium-90 is 28.8 years.

5 0

3 years ago

Why do objects cool down

zhannawk [14.2K]

Answer:

wla dyan ang sagut ehh baka mali yan

7 0

3 years ago

Which one of these compounds is an ionic compound? question 18 options: n2 na2o co2?

spayn [35]

Types of Bonds can be predicted by calculating the difference in electronegativity.

If, Electronegativity difference is,

Less than 0.4 then it is Non Polar Covalent

Between 0.4 and 1.7 then it is Polar Covalent

Greater than 1.7 then it is Ionic

For N₂,

E.N of Nitrogen = 3.04

________

E.N Difference 0.00 (Non Polar Covalent)

For Na₂O,

E.N of Oxygen = 3.44

E.N of Sodium = 0.93

________

E.N Difference 2.51 (Ionic)

For CO₂,

E.N of Oxygen = 3.44

E.N of Carbon = 2.55

________

E.N Difference 0.89 (Polar Covalent)

4 0

3 years ago