Answer:
400 or 4x102 indicates only onesignificant figure. (To indicate that the trailing zeros are significant a decimal point must be added. 400. has threesignificant digits and is written as 4.00x102 in scientific notation.) Exact numbers have an infinite number of significant digits but they are generally not reported.
Answer:
The number of protons in the nucleus of the atom is equal to the atomic number (Z). The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus.
Answer:
The minimum resistance is 25 ohms.
Explanation:
Resistance of each resistor is 100 ohms. When resistors are connected in parallel, the equivalent resistance is lowest. For parallel combination, the equivalent resistance is given by :
Here, all resistors are 100 ohms. So,
So, the minimum resistance is 25 ohms.
The moles are the estimation of the quantities like the molecules and the atoms. There are 7.984 moles of aluminum present in the 2.154 × 10⁻¹ kg substance. Thus, option b is correct.
<h3>What are moles?</h3>
The moles give the estimation of the smaller entities by the ratio of mass or weight to the molar mass of the substance.
The formula for moles is given as,
Moles = mass ÷ molar mass
Given,
Mass of aluminium = 2.154 × 10⁻¹ kg = 2.154 × 10² gm
Molar mass of Al = 26.9 g/mol
Substituting values above:
Moles = 2.154 × 10² gm ÷ 26.9 g/ mol
= 7.984 mol
Therefore, option. 7.984 moles of aluminum are present.
Learn more about moles here:
brainly.com/question/15209553
#SPJ4
The right answer is ...
number 3
Scientists with different backgrounds and areas of expertise each contribute to the solution
