The table below shows two types of electromagnetic waves and three random applications of electromagnetic waves. Type of Wave Applications of Wave
X-rays 1. Show the heat released by astronomical objects
Ultraviolet rays 2. Study stars having high temperature
3. Detect collection of gas, dust, and plasma

Which of these best matches the waves with their applications?
X-rays—2 and ultraviolet rays—3
X-rays—3 and ultraviolet rays—2
X-rays—1 and ultraviolet rays—2
X-rays—2 and ultraviolet rays—1

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

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