Answer: Streak
Explanation: The color of a mineral in powdered form is called the mineral's streak. To find a mineral's streak, the mineral is rubbed against a piece of unglazed porcelain called a streak plate. The mark left on the streak plate is the streak.
<u>Answer:</u> The total pressure inside the container is 77.9 kPa
<u>Explanation:</u>
Dalton's law of partial pressure states that the total pressure of the system is equal to the sum of partial pressure of each component present in it.
To calculate the total pressure inside the container, we use the law given by Dalton, which is:

We are given:
Vapor pressure of oxygen gas,
= 40.9 kPa
Vapor pressure of nitrogen gas,
= 23.3 kPa
Vapor pressure of argon,
= 13.7 kPa
Putting values in above equation, we get:

Hence, the total pressure inside the container is 77.9 kPa
Answer:
Answer below.
Explanation:
An exothermic reaction is a chemical reaction that releases energy through light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation: reactants → products + energy.
Answer:
They all have the same number of protons but different numbers of neutrons.
Explanation:
These are called isotopes. Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
The atomic number is the number of protons in an atom. For a neutral atom, it is the same as the number of electrons.
The mass number is the number of protons and neutrons in an atom.
silicon-28 (28Si)
silicon-29 (29Si)
silicon-30 (30Si)
All of these isotopes have an atomic number of 16
Now let us chech for the neutrons:
Number of neutrons = mass number - atomic number:
for silicon-28 (28Si) : 28-16 = 12 neutrons
silicon-29 (29Si)
: 29-16 = 13 neutrons
silicon-30 (30Si): 20-16 = 14 neutrons.