Answer:
must have the same number of protons
<h3>
Answer:</h3>
2000 atoms
<h3>
Explanation:</h3>
We are given the following;
Initial number of atoms of radium-226 as 8000 atoms
Time taken for the decay 3200 years
We are required to determine the number of atoms that will remain after 3200 years.
We need to know the half life of Radium
- Half life is the time taken by a radio active material to decay by half of its initial amount.
- Half life of Radium-226 is 1600 years
- Therefore, using the formula;
Remaining amount = Original amount × 0.5^n
where n is the number of half lives
n = 3200 years ÷ 1600 years
= 2
Therefore;
Remaining amount = 8000 atoms × 0.5^2
= 8000 × 0.25
= 2000 atoms
Thus, the number of radium-226 that will remain after 3200 years is 2000 atoms.
To know the answer, compare the oxidation number of the element in the reactant and the product side. The oxidation number of Al was originally +3, then became 0 after the reaction. On the other hand, Fe was originally 0, then became +2 after the reaction. When the element is oxidized, it oxidation number increases. <em>Thus, the element oxidized is Fe.</em>
Answer:
Malachite
Explanation:
Malachite is the only listed compound that must contain copper and oxygen.
Copper and oxygen are both elements found on the periodic table. They have the following symbols;
Copper = Cu
Oxygen = O
From the given choices, only option 1 has the symbol Cu and O.
So only malachite contains both copper and oxygen.
Answer:
Spindle fibers form.
DNA condenses into chromosomes.
Explanation:
Prophase is the first stage of mitosis. Mitosis produces 2 daughter cells from a parental cell.
Spindle fibers form - this is true. During prophase, the mitotic spindle forms. Later during mitosis the spindle attaches to the centromere of chromosomes and pulls them to opposite ends of the cell prior to division
DNA condenses into chromosomes. - this is true. In the nucleus during interphase, the DNA is relatively loosely compacted. However, prior to division, the DNA is condensed into structures called chromosomes which are then paired up and distributed to the daughter cell.
Chromosomes move to opposite ends of the cell. - this is false. This happens during anaphase
Nuclear membrane begins to re-form. - this is false. This happens during telophase.
