She can put chalk in vinegar as the vinegar will disintegrate the chalk chemically demonstrating chemical changes. But for physical changes she can break the chalk into small pieces by smashing it with something or her hand.
higher temp = higher energy = higher frequency = shorter wavelength
Explanation:
Mirrors consist of reflecting surfaces that reflect light.
Reflection is a phenomenon of light wave (but also of other types of waves) in which a ray of light hits a surface, and then it bounces back into the original medium at a certain angle.
The direction of the reflected ray is determined by the law of reflection:
- The incident ray, the reflected ray and the normal to the surface all lie in the same plane
- The angle of reflection is equal to the angle of incidence (where both angles are measured between the ray and the normal to the surface)
A plane mirror is a type of mirror consisting of a straight surface. As a result, light incident perpendicular to the surface is reflected back exactly in the opposite direction.
The image formed by a plane mirror is:
- The same size as the object
- Virtual (it is located behind the mirror)
- Laterally inverted
- Upright
1). Take a sample of the substance. The sample should be the largest
possible that will allow it to be be easily handled and the following steps
to be performed with it.
(The density doesn't depend on the size of the sample, and every sample
of the same substance has the same density. But using a larger sample
can improve the accuracy of the measurements you make, and therefore
improve the accuracy of the density you derive for the substance.)
2). Ask or measure the mass of the sample.
3). Ask or measure the volume of the sample.
4). Divide the mass by the volume. Their quotient is the density
of the substance.
