Ask question

Ask question

All categories

4 years ago

10

In physical science lab, Ben and Jerry added small pieces of magnesium to hydrochloric acid. They noticed that bubbles formed, t

he test tube got hot, and the magnesium disappeared. What is a sign that a chemical reaction has taken place in this experiment?

1 answer:

svetoff [14.1K]4 years ago

6 0

The signs of a chemical reaction are bubbles, heat an magnesium disappearing.

You might be interested in

Water occupies two main fluid compartments within the body, the intracellular fluid compartment and the extracellular fluid comp

nadezda [96]

Answer:

C. Approx. Two thirds of the water is in the ICF compartment

Explanation:

The body cells are bathed in fluids internally and externally. The water inside the cells make up about 42% of the total body weight and is called the intracellular fluid (ICF). The rest of the fluid outside the cells is called extracellular fluid (ECF) and is separated from the intracellular fluid by a semipermeable membrane that surrounds the cell, and only allows fluid to flow in and out of the cells, but prevents unwanted molecules or materials from getting in.

5 0

3 years ago

The mass of helium gas in a balloon is ________.

Nady [450]

Answer:

Option (b).

Explanation:

Mass of an object is defined as the amount of matter contained in it. In this case, the mass of helium gas in a balloon is the amount of matter inside the balloon. It is independent of the outside condition.

Hence, out of 4 options, the correct option is (b).

3 0

4 years ago

To find some of the parameters characterizing an object moving in a circular orbit.The motivation for Isaac Newton to discover h

tamaranim1 [39]

Answer:

$K = \frac{GMm}{2r}$

$T^2 = 4\pi^2(\frac{r^3}{GM})$

Explanation:

As we know that for a satellite the force of gravitation is equal to the centripetal force

so we will have

$F = \frac{GMm}{r^2}$

$\frac{mv^2}{r} = \frac{GMm}{r^2}$

so we know that kinetic energy is given as

$K = \frac{1}{2}mv^2$

so we have

$K = \frac{GMm}{2r}$

now for time period we know

$T = \frac{2\pi r}{v}$

from above expression of kinetic energy we have

$v = \sqrt{\frac{GM}{r}}$

so we have

$T = \frac{2\pi r}{\sqrt{\frac{GM}{r}}}$

so square of time period is given as

$T^2 = 4\pi^2(\frac{r^3}{GM})$

3 0

4 years ago

A rope with a mass density of 1 kg/m has one end tied to a vertical support. You hold the other end so that the rope is horizont

PIT_PIT [208]

Answer:

$v' = 2.83 m/s$

Explanation:

Velocity of wave in stretched string is given by the formula

$v = \sqrt{\frac{T}{\mu}}$

here we know that

T = 4 N

also we know that linear mass density is given as

$\mu = 1 kg/m$

so we have

$v = \sqrt{\frac{4}{1}} = 2 m/s$

now the tension in the string is double

so the velocity is given as

$v' = \sqrt{\frac{8}{1}} = 2\sqrt2 m/s$

$v' = 2.83 m/s$

4 0

4 years ago

How do galaxies vary?

givi [52]

The universe has trillions of galaxies and counting. Astronomers give names to each galaxy base on its shape (e.i, Sombrero galaxy, Milkyway Galazy, ect,.).

Also, the size of the galaxy is taken into account and their color.

4 0

3 years ago