Which of the following elements belong to the d-block of the periodic table?

Question 2 options:

transition metals

noble gases

halogens

alkali metals

What happens to the half-life and mass of reactants broken down during a nuclear decay reaction? The half-life of the reactants in a nuclear decay reaction remains constant over time, and the mass of the reactants that are consumed stays the same.

Some substances have the same chemical composition, but their atoms are arranged differently. A classic example is carbon. A pencil lead is made of graphite, which contains only carbon atoms. A diamond also contains only carbon atoms.

Why is it important that the polymer membrane in a PEM fuel cell allows only protons to move through it? It forces the electrons to move through an external circuit, where they can do work.

Caclulate the pH for a solution with an [H+] = 9.75 x10-4

Mixtures are 'separated through ._changes. compound physical mixtures

What is the chemical formula of a compound that is composed of the ions Ca2 + and br-

What element is likely to form an ionic compound with chlorine?

Will a parachute slow a skydiver more at a very high altitude or a lower altitude?

Carbon monoxide is: Only found in large cities An odorless, colorless, toxic gas Healthy to breath in A danger when driving on the open highway

What is a potential benefit of fuel cell cars? increased efficiency converting gasoline to energy no recharging necessary decreased automobile cost larger engines