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Firlakuza [10]
3 years ago
5

Which is a sign of a chemical change? A) Ice cream left at room temperature melts. B) Calcium chloride is dissolved in H2O and d

isappears. C) Paint on a freshly painted wall dries and is no longer sticky. D) When H2S gas is bubbled into a lead acetate solution, a precipitate forms.
Physics
2 answers:
Eduardwww [97]3 years ago
7 0

D, because a physical change is when something changes but doesn't change into a new substance. A chemical change is when something changes into a new substance.

Katarina [22]3 years ago
5 0
Chemical change is any change that results in the formation of new chemical substances. (Thanks to google)

This the answer is D
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What is the Genetic Modification Process?<br><br> Brainlyist for the best answer
Dovator [93]

Answer:

Production of GMOs is a multistage process which can be summarized as follows:

1. identification of the gene interest;

2. isolation of the gene of interest;

3. amplifying the gene to produce many copies;

4. associating the gene with an appropriate promoter and poly A sequence and insertion into plasmids;

5. multiplying the plasmid in bacteria and recovering the cloned construct for injection;

6. transference of the construct into the recipient tissue, usually fertilized eggs;

7. integration of gene into recipient genome;

8. expression of gene in recipient genome; and

9. inheritance of gene through further generations.

6 0
2 years ago
Read 2 more answers
Which of the following describes how the current in a circuit can be increased? Select all that apply.
Anettt [7]

Answer:

B. and D. would be my best guess.

Explanation:

The reason why is because if you lower the resistance, the voltage will be higher, and if you higher the voltage, the resistance would be lower and the voltage would higher.

5 0
3 years ago
The speed of a moving bullet can be deter-
Bad White [126]

Answer:

<em>v = 381 m/s</em>

Explanation:

<u>Linear Speed</u>

The linear speed of the bullet is calculated by the formula:

\displaystyle v=\frac{x}{t}

Where:

x = Distance traveled

t = Time needed to travel x

We are given the distance the bullet travels x=61 cm = 0.61 m. We need to determine the time the bullet took to make the holes between the two disks.

The formula for the angular speed of a rotating object is:

\displaystyle \omega=\frac{\theta}{t}

Where θ is the angular displacement and t is the time. Solving for t:

\displaystyle t=\frac{\theta}{\omega}

The angular displacement is θ=14°. Converting to radians:

\theta=14*\pi/180=0.2443\ rad

The angular speed is w=1436 rev/min. Converting to rad/s:

\omega = 1436*2\pi/60=150.3776\ rad/s

Thus the time is:

\displaystyle t=\frac{0.2443\ rad}{150.3776\ rad/s}

t = 0.0016 s

Thus the speed of the bullet is:

\displaystyle v=\frac{0.61}{0.0016}

v = 381 m/s

7 0
3 years ago
Explain what happens to the pitch of a cell phone ring when the wavelength of a sound wave increases
max2010maxim [7]

You get a more low sound.  

Conversely, when the wavelength becomes shorter you get a more treble sound.

;-)

4 0
3 years ago
Read 2 more answers
Thermal conductivity of a material is given as 129Btuft–¹ h–¹°F–¹.Calculate this thermal conductivity in Jm–¹s–¹°C–¹(Given: 1Btu
ss7ja [257]

Answer:

223.25 $\text{Jm}^{-1}\text{s}^{-1}^\circ\text{C}^{-1}$

Explanation:

The thermal conductivity of an object is defined as the measure or the ability of the object to transfer heat or conduct heat through its body.

In the context, the thermal conductivity of the material is given as

$=129 \text{ Btu ft}^{-1}\text{h}^{-1}^\circ\text{F}^{-1}$

And it is given that :

1 Btu = 1055 J

1 ft = 0.3048 m

$1^\circ F = \frac{5}{9}^\circ C$

We know that 1 h = 3600 s

So the thermal conductivity of the material in $\text{Jm}^{-1}\text{s}^{-1}^\circ\text{C}^{-1}$ is  :

Thermal conductivity :

$=\frac{129 \text{ Btu}}{1 \text{ ft }\times \text{1 h}\times 1^\circ\text{F}}$

$=\frac{129 \times 1055 \text{ J}}{0.3048 \text{ m} \ \times 3600 \text{ s}\ \times \frac{5}{9}^\circ \text{C}}$

=  223.25 $\text{Jm}^{-1}\text{s}^{-1}^\circ\text{C}^{-1}$

3 0
3 years ago
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