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tatyana61 [14]
3 years ago
8

Which event always involves a chemical change?

Chemistry
1 answer:
TEA [102]3 years ago
6 0

Answer:

<h2><u><em>Burning</em></u></h2>

Explanation:

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A mileage test is conducted for a new car model. Thirty randomly selected cars are driven for a month and the mileage is measure
Leni [432]

Answer:  (27.81,\ 29.39)

Explanation:

Given : Sample size : n= 30 , it means it is a large sample (n≥ 30), so we use z-test .

Significance level : \alpha: 1-0.95=0.05

Critical value: z_{\alpha/2}=1.96

Sample mean : \overline{x}=28.6

Standard deviation : \sigma=2.2

The formula to find the confidence interval is given by :-

\overline{x}\pm z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}

i.e. 28.6\pm (1.96)\dfrac{2.2}{\sqrt{30}}

i.e. 28.6\pm 0.787259889321

\approx28.6\pm 0.79=(28.6-0.79,28.6+0.79)=(27.81,\ 29.39)

Hence, the 95% confidence interval for the mean mpg in the entire population of that car model = (27.81,\ 29.39)

4 0
3 years ago
What describes the behavior of an ideal gas?
valina [46]

Answer:

The answer is D

Explanation:

for a p e x

5 0
3 years ago
What happens in the redox reaction below? Select all that apply.
vladimir2022 [97]

Answer:

B- Sodium loses an electron.

D- Fluorine gains an electron.

Sodium is oxidized.

Explanation:

The reaction equation is given as:

        Na  + F →  NaF

In this reaction, Na is the reducing agent. It loses an electron and then becomes oxidized. By so doing, Na becomes isoelectronic with Neon.

Fluorine gains the electron and then becomes reduced. This makes fluorine also isoelectronic with Neon.

This separation of charges on the two species leads to an electrostatic attraction which forms the ionic bonds.

6 0
3 years ago
Webb has calculated the percent composition of a compound. How can he check his result?
fenix001 [56]
Webb has calculated the percent composition of a compound. He can check his result by adding them to see if they equal up to 100. Why? Well, percent composition tells the quantity of elements with 100 as a base of total amount. This means that it will have to add to 100 to check the result. You would add up all of the values of percent composition of elements to see if they equal 100, and if they do, the results are accurate.

Your final answer: Webb can check his result by seeing if they add up to 100, considering that is the base total quantity.
7 0
2 years ago
What subatomic particle is most involved in making chemical bonds?
frozen [14]
An electron i hope this helps
5 0
3 years ago
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