<h2>Answer </h2>
Matter
<u>Explanation </u>
A matter has distinct properties and composition that never vary. The matter is anything which possesses mass and occupies space. The matter has different characteristics and a distribution that does not change from unit to unit. Materials which cannot be disintegrated into simpler materials. Each is made of only one kind of atom in subatomic level. For example, a chair, table, and similar everything that has mass and occupies space is matter.
Answer:

Explanation:
The two requirements for a measurement are a <u>number</u> and a <u>unit.</u>
For example, here is a measurement:
38.6 cm
The <u>number</u> is 38.6 and the <u>unit</u> is cm, or centimeters.
Therefore, both <em>number </em>and <em>unit</em> are correct.
Answer:
Higher frequency
Explanation:
We can imagine a chemical bond between two atoms as if it were two balls connected by a spring.
According to Hooke's Law, the stretching frequency f is

where µ is the reduced mass of the system

The strength of the bond is analogous to k, the force constant of the spring. Then,

Thus, the stronger the bond, the greater the frequency of vibration.